# Glossary > The words of mobile design systems, each with its Apple name, its Material 3 name and its value in Appetite UI, a Figma UI kit for iOS and Android apps. Page: https://www.appetiteui.com/glossary. Every term with a page also has a markdown twin at its URL plus .md. The site map for agents: https://www.appetiteui.com/llms.txt. ## Which values differ between iOS and Android? | What it sets | iOS | Android | Variable | | --- | --- | --- | --- | | Minimum touch target | 44 pt | 48 dp | `platform/min-touch-target` | | Top safe area | 59 pt | 52 dp | `grid/safe-area/top` | | Bottom safe area | 34 pt | 24 dp | `grid/safe-area/bottom` | | Top bar height | 44 pt | 64 dp | `platform/bar/top-height` | | Tab bar height | 49 pt | 64 dp | `platform/bar/bottom-height` | | List row, minimum height | 44 pt | 56 dp | `platform/list-row/min-height` | | Switch track width | 64 pt | 52 dp | `platform/switch/track-width` | | Switch track height | 28 pt | 32 dp | `platform/switch/track-height` | | Control corner | 8 pt | Fully round | `platform/control/corner` | | Sheet corner | 12 pt | 28 dp | `platform/sheet/corner` | | Dialog corner | 12 pt | 28 dp | `platform/dialog/corner` | | Screen side padding | 16 pt | 16 dp | `platform/screen-padding` | ## Tokens and variables - **[Design tokens](https://www.appetiteui.com/glossary/design-tokens)**: A design token is a named design decision, such as a color, a spacing step or a radius, stored once and read by design files and code alike. Changing the token changes every place that reads it. Apple: No token system in the HIG; colors and metrics are named system values. Material 3: Design tokens, such as md.sys.color.primary. Appetite UI: Figma variables in six collections, exported as DTCG. - **[Semantic tokens](https://www.appetiteui.com/glossary/semantic-tokens)**: A semantic token names a role, such as bg/weak-50 or text/strong-950, and points at a primitive token that holds the raw value. Components bind to the role, never to the primitive. Apple: Semantic colors, such as label and systemBackground. Material 3: Color roles, such as primary and surface-container. Appetite UI: Color Tokens collection, roles such as brand/base and bg/weak-50. - **[Variable modes](https://www.appetiteui.com/glossary/variable-modes)**: A mode is one column of values in a Figma variable collection, such as Light and Dark. A frame set to a mode resolves every variable in it against that column. Apple: Appearance (light and dark) and size classes. Material 3: Color schemes (light and dark) and window size classes. Appetite UI: Modes of the Color Tokens and Platform collections. - **[DTCG tokens](https://www.appetiteui.com/glossary/dtcg)**: DTCG is the file format of the W3C Design Tokens Community Group: JSON in which each token has a $value and a $type. Tools that read it can turn one file into code for every platform. Apple: No equivalent. Material 3: No equivalent; Material Theme Builder exports its own JSON. Appetite UI: tokens.json, W3C DTCG. - **[Dark mode](https://www.appetiteui.com/glossary/dark-mode)**: Dark mode is a second set of values for the same color roles, chosen for a dark background. Done with tokens, it is one mode switch, not a second set of frames. Apple: Dark Mode. Material 3: Dark theme. Appetite UI: The Dark mode of the Color Tokens collection. - **[Platform Bridge](https://www.appetiteui.com/glossary#platform-bridge)**: Platform Bridge is the Appetite UI collection that maps Apple and Material 3 color and type slots to your brand tokens. One mode switch returns each platform’s own values. Apple: Maps onto iOS system colors. Material 3: Maps onto Material 3 color roles. Appetite UI: Platform Bridge collection, Brand and System modes. - **[Motion, easing and duration](https://www.appetiteui.com/glossary/motion)**: Motion is how a screen changes over time, set by an easing curve and a duration. Material defines named easing and duration tokens, and Apple’s guidance asks for motion that is purposeful, brief and optional. Apple: Motion: purposeful, optional, brief. Material 3: Easing and duration, with standard, decelerate and accelerate curves. Appetite UI: motion/duration and motion/easing tokens. - **[Accent color](https://www.appetiteui.com/glossary/accent-color)**: The accent color is the one color an app uses for what can be tapped and what is selected. iOS calls it the tint and Material 3 calls it the primary role. Apple: Tint color, system accent. Material 3: Primary color role. Appetite UI: brand/base. - **[Dynamic Type and font scaling](https://www.appetiteui.com/glossary/dynamic-type)**: Dynamic Type is the iOS setting that lets people choose the size of text, and a design supports it by using text styles. Android has the same idea through font scale and text sizes in sp. Apple: Dynamic Type, text styles. Material 3: Type scale roles, sizes in sp. Appetite UI: typography scale. - **[Color contrast](https://www.appetiteui.com/glossary/color-contrast)**: Color contrast is the difference in luminance between content and its background, written as a ratio. WCAG asks for 4.5 to 1 for normal text and 3 to 1 for large text and for the parts of controls. Apple: System colors with increased contrast variants. Material 3: Color roles that pair content with its container. Appetite UI: Semantic color tokens in Light and Dark. ## Layout, type and touch - **[Touch target](https://www.appetiteui.com/glossary/touch-target)**: A touch target is the area that responds to a tap, which can be larger than the control people see. Apple gives 44 by 44 points as the default control size on iPhone, and Material asks for at least 48 by 48 dp. Apple: Hit region, 44 by 44 pt by default, 28 by 28 pt at the smallest. Material 3: Touch target, 48 by 48 dp minimum. Appetite UI: platform/min-touch-target. - **[Safe area](https://www.appetiteui.com/glossary/safe-area)**: The safe area is the part of the screen no system element covers: inside the status bar, the Dynamic Island or camera, the home indicator and the rounded corners. Content goes inside it, backgrounds may run past it. Apple: Safe area and layout margins. Material 3: Window insets and edge to edge. Appetite UI: grid/safe-area/top and grid/safe-area/bottom. - **[Spacing scale](https://www.appetiteui.com/glossary/spacing-scale)**: A spacing scale is the fixed set of distances every padding and gap in an interface is taken from, usually multiples of 4 or 8. Picking from a scale instead of typing numbers keeps a whole app on one rhythm. Apple: No named scale; layout margins and spacing are set per component. Material 3: An 8 dp grid for layout and a 4 dp grid for small elements. Appetite UI: dimensions/spacing/*, a 4 pt scale. - **[Type scale](https://www.appetiteui.com/glossary/type-scale)**: A type scale is the set of text sizes an interface uses, each a step with its own size, line height and weight. Apple names its steps Dynamic Type text styles, such as body and title1, and Material 3 names them roles, such as bodyLarge and headlineSmall. Apple: Dynamic Type text styles, largeTitle to caption2. Material 3: Type scale roles: display, headline, title, body, label. Appetite UI: Typography collection, steps xs to 6xl. - **[Corner radius](https://www.appetiteui.com/glossary/corner-radius)**: Corner radius is how round the corners of a surface or control are. Apple and Material round different things by different amounts, so one value rarely suits both. Apple: Corner radius. Material 3: Shape, corner tokens. Appetite UI: platform/*/corner and the radius scale. - **[Status bar](https://www.appetiteui.com/glossary/status-bar)**: The status bar is the strip at the top of the screen with the time, signal and battery, drawn by the system over every app. An app leaves room for it and chooses only whether its content is light or dark. Apple: Status bar. Material 3: Status bar, one of the system bars. Appetite UI: iOS / Status Bar, and grid/safe-area/top on Android. - **[Large title](https://www.appetiteui.com/glossary/large-title)**: A large title is the oversized screen heading in an iOS navigation bar that shrinks to a standard title as the content scrolls. Material 3 has a similar pattern in the Medium and Large top app bars. Apple: Large title in a navigation bar. Material 3: Medium and Large top app bar. Appetite UI: Top Bar, lg. - **[Points and dp](https://www.appetiteui.com/glossary/points-and-dp)**: A point (pt) is the unit of layout on iOS and a dp is the unit on Android; both are virtual pixels that the system scales to the screen’s density. A Figma frame of 402 by 874 is in points, not in device pixels. Apple: Point. Material 3: Density-independent pixel (dp). Appetite UI: Frame units, no suffix. - **[Size classes](https://www.appetiteui.com/glossary/size-classes)**: Size classes describe how much space an app has, so a layout can adapt. iOS has compact and regular size classes for each dimension, and Android has compact, medium and expanded window size classes by width. Apple: Horizontal and vertical size classes: compact, regular. Material 3: Window size classes: compact, medium, expanded. Appetite UI: Platform modes ios-md, ios-lg, android. ## Components - **[Tab bar](https://www.appetiteui.com/glossary/tab-bar)**: A tab bar is the row of top level destinations at the bottom of an app. Apple calls it a tab bar; Material 3 calls the same thing a navigation bar. Apple: Tab bar. Material 3: Navigation bar. Appetite UI: Navigation. - **[Top app bar](https://www.appetiteui.com/glossary/top-app-bar)**: The bar at the top of a screen with its title, a way back and a few actions. Material 3 calls it the top app bar; Apple calls it a navigation bar. Apple: Navigation bar. Material 3: Top app bar. Appetite UI: Top Bar. - **[Navigation drawer](https://www.appetiteui.com/glossary/navigation-drawer)**: A navigation drawer is a panel that slides in from the leading edge with an app’s top level destinations, for apps that have more than a tab bar holds. Material 3 has one; iOS has no drawer and uses a tab bar, or a sidebar on iPad. Apple: No drawer; a tab bar, or a sidebar on iPad. Material 3: Navigation drawer, being replaced by the expanded navigation rail. Appetite UI: Navigation Drawer. - **[Toggle and switch](https://www.appetiteui.com/glossary/toggle-switch)**: A switch turns one setting on or off, and the change takes effect at once. Apple calls the control a toggle, Material 3 a switch. Apple: Toggle. Material 3: Switch. Appetite UI: Toggle. - **[Chip](https://www.appetiteui.com/glossary/chip)**: A chip is a compact capsule that filters a list, picks from a set or shows an entry someone added. It is a Material 3 component with no counterpart on the kit’s Apple pages. Apple: No chip on the kit’s Apple pages. Material 3: Chip, 32 high at radius 8. Appetite UI: Chip. - **[Segmented control](https://www.appetiteui.com/glossary/segmented-control)**: A segmented control switches between two to five views of the same content, one segment selected at a time. Material 3 calls it a segmented button. Apple: Segmented control. Material 3: Segmented button. Appetite UI: Segmented Control. - **[Floating action button](https://www.appetiteui.com/glossary/floating-action-button)**: A floating action button is a round button that floats over the content for the one action a screen exists for, such as a new task. It is a Material component; iOS puts the same action in a bar. Apple: No component; the action goes in a toolbar or the navigation bar. Material 3: Floating action button and extended FAB. Appetite UI: Floating Action Button, in /docs/button. - **[List row](https://www.appetiteui.com/glossary#list-row)**: A list row is one line of a list: a leading icon or avatar, a title and an optional line under it, and a trailing chevron, value or control. iOS sets a 44 minimum, Material sets the height by lines of text. Apple: List row, 44 minimum. Material 3: List item, 56, 72 or 88 by lines. Appetite UI: List. - **[Text field](https://www.appetiteui.com/glossary/text-field)**: A text field is the control in which people type a single line of text, such as an email, a name or a search term. iOS calls it a Text Field, and Material 3 draws it as a Filled or Outlined Text Field. Apple: Text Field and Secure Field. Material 3: Text field, Filled or Outlined. Appetite UI: Input. - **[Search bar](https://www.appetiteui.com/glossary/search-bar)**: A search bar is the field in which people type a query to find content in an app. Apple calls it a search field and Material 3 calls it a search bar, each with suggestions below it. Apple: Search field. Material 3: Search bar and search view. Appetite UI: Search. - **[Picker](https://www.appetiteui.com/glossary/picker)**: A picker is the control that lets people choose a value from a set instead of typing it, most often a date or a time. iOS offers compact, inline and wheel date pickers, and Material 3 offers modal date pickers and dial or keyboard time pickers. Apple: Date picker and Picker. Material 3: Date picker and time picker. Appetite UI: Date Picker and Time Picker. - **[Slider](https://www.appetiteui.com/glossary/slider)**: A slider is a control for choosing a value from a continuous range by dragging a thumb along a track. iOS calls it a Slider, and Material 3 adds a Range slider with two thumbs. Apple: Slider. Material 3: Slider and Range slider. Appetite UI: Slider and Range Slider. - **[Checkbox and radio button](https://www.appetiteui.com/glossary/checkbox-radio-button)**: A checkbox lets people select any number of options, and a radio button lets them select exactly one. Material 3 has both on Android, while iOS uses a toggle or a list row with a checkmark instead. Apple: No checkbox: Toggle, or a list row with a checkmark. Material 3: Checkbox and Radio button. Appetite UI: Checkbox and Radio. - **[Card](https://www.appetiteui.com/glossary/card)**: A card is a container that groups related content and actions about one subject, such as a place, a product or an article. Material 3 has a Card component; iOS groups the same content in list cells. Apple: No card: List cells in plain, grouped and inset grouped styles. Material 3: Card: elevated, filled and outlined. Appetite UI: Card. - **[SF Symbols and Material Symbols](https://www.appetiteui.com/glossary/icon-sets)**: SF Symbols is the icon set of Apple platforms and Material Symbols is the icon set of Android, both variable fonts with weights that match text. Appetite UI draws its icons from one outline set for both. Apple: SF Symbols. Material 3: Material Symbols. Appetite UI: Lucide, one outline set. - **[Button](https://www.appetiteui.com/glossary/button)**: A button is the control that starts an action when tapped. iOS styles it as borderless, bordered or bordered prominent, and Material 3 offers filled, tonal, outlined, elevated and text buttons. Apple: Button: borderless, bordered, bordered prominent. Material 3: Button: filled, tonal, outlined, elevated, text. Appetite UI: Button. - **[Tabs](https://www.appetiteui.com/glossary/tabs)**: Tabs switch between related views inside one screen, with one tab selected at a time. Material 3 has primary and secondary tabs, and iOS has no top tabs: its tab bar moves between top-level destinations. Apple: No top tabs: segmented control; the Tab bar is for destinations. Material 3: Primary tabs and secondary tabs. Appetite UI: Tab. - **[Toolbar](https://www.appetiteui.com/glossary/toolbar)**: A toolbar is a bar of actions for the current view, placed at the bottom or top edge. iOS calls it a Toolbar and Material 3 has the bottom app bar, which can carry a floating action button. Apple: Toolbar. Material 3: Bottom app bar. Appetite UI: Toolbar. - **[Divider](https://www.appetiteui.com/glossary/divider)**: A divider is a thin line that separates items or groups of content. iOS calls it a separator, in lists and as a Divider view, and Material 3 has the divider with a 1 dp regular and an 8 dp heavy weight. Apple: Separator and Divider. Material 3: Divider: full width, inset. Appetite UI: Divider. - **[Badge](https://www.appetiteui.com/glossary/badge)**: A badge is a small mark on an item that says something is new or counts it, as a dot or a number. iOS puts it on a tab or a list row and Material 3 has small and large badges. Apple: Badge, on a tab item or a list row. Material 3: Badge: small dot or large with a number. Appetite UI: Badge. - **[Accordion](https://www.appetiteui.com/glossary/accordion)**: An accordion is a list of rows that each expand to show more content and collapse to hide it. iOS calls the pattern a disclosure group, and Material 3 has no accordion component. Apple: Disclosure group. Material 3: No component: expandable list item in code. Appetite UI: Accordion. - **[Stepper](https://www.appetiteui.com/glossary/stepper)**: A stepper is a control with a minus and a plus that changes a value one step at a time. A step indicator is a different thing that shows where someone is in a flow; iOS has the first and Material 3 has neither. Apple: Stepper. Material 3: No stepper or step indicator. Appetite UI: Stepper and Progress Steps. - **[Page control](https://www.appetiteui.com/glossary/page-control)**: A page control is a row of small dots that shows which page of a swipeable sequence is current. iOS calls it a Page Control, and Material 3 has no matching component. Apple: Page control. Material 3: No page control; carousels. Appetite UI: Pagination. - **[Dropdown menu](https://www.appetiteui.com/glossary/dropdown-menu)**: A dropdown menu is a list that opens from a visible control to pick an option or run a command. iOS splits it into a pop-up button for options and a pull-down button for commands, and Material 3 has a dropdown menu. Apple: Pop-up button and pull-down button. Material 3: Dropdown menu. Appetite UI: DropdownMenu. - **[Carousel](https://www.appetiteui.com/glossary/carousel)**: A carousel is a row of items that people scroll sideways, such as images or cards. Material 3 has a Carousel with multi-browse, uncontained, hero and full-screen layouts, and iOS has no component of that name. Apple: No carousel component: paged or scrolling content with a page control. Material 3: Carousel: multi-browse, uncontained, hero, full-screen. Appetite UI: Card and Pagination, dots. - **[Chart](https://www.appetiteui.com/glossary/chart)**: A chart turns a set of numbers into a shape people can read at a glance. On a phone the choice is by the shape of the data: a trend takes a line, a comparison takes bars, a share of a whole takes a donut. Apple: Charts, built with Swift Charts. Material 3: No chart component in the file. Appetite UI: Chart, Legend and Sparkline. - **[Data table](https://www.appetiteui.com/glossary/data-table)**: A data table lays values out in rows and columns so they can be compared. On a phone it is wider than the screen, so it scrolls sideways under a pinned lead column and its headers can sort. Apple: Table, as a list or SwiftUI Table. Material 3: No table in the file. Appetite UI: Table. - **[File upload](https://www.appetiteui.com/glossary/file-upload)**: File upload is the control that lets people add a photo or a document, then shows the file and its progress. On a phone the selection itself is handed to a system picker and the app draws the surface around it. Apple: Document and photo pickers, Files app. Material 3: No component in the file. Appetite UI: File Upload. - **[AI chat UI](https://www.appetiteui.com/glossary/ai-chat-ui)**: An AI chat UI is a thread of messages and a prompt input where the answer arrives while it is written. Neither iOS nor Material 3 ships a component for it, so the message row and the composer are drawn by the app. Apple: Generative AI guidance, no chat component. Material 3: No chat component. Appetite UI: Message and Prompt composer. - **[Settings screen](https://www.appetiteui.com/glossary/settings-screen)**: A settings screen is a grouped list of preferences, with a switch for each yes or no choice. Apple asks for good defaults and as few settings as possible. Apple: Settings. Material 3: Settings pattern, list with switches. Appetite UI: Settings screens. - **[Form validation](https://www.appetiteui.com/glossary/form-validation)**: Form validation checks what people enter and says what is wrong near the field, as soon as the value is entered. Apple asks to validate dynamically so mistakes are not found after a long form. Apple: Entering data: text field with dynamic validation. Material 3: Text field error state. Appetite UI: Input error state. - **[Navigation rail](https://www.appetiteui.com/glossary/navigation-rail)**: A navigation rail is a vertical bar of top-level destinations at the edge of a medium or large screen. Material 3 has it in collapsed and expanded forms, and iOS moves the same job into a sidebar or a tab bar. Apple: Sidebar, or a tab bar that adapts to one. Material 3: Navigation rail: collapsed and expanded. Appetite UI: Duo control rail. - **[Sidebar](https://www.appetiteui.com/glossary/sidebar)**: A sidebar is a panel at the leading edge that lists the main areas of an app. iOS uses it on iPad and Mac, where it can float on Liquid Glass; Material 3 has the navigation drawer and the rail. Apple: Sidebar. Material 3: Navigation drawer or rail. Appetite UI: Not drawn. - **[Split view](https://www.appetiteui.com/glossary/split-view)**: A split view shows several levels of an app at once: a primary pane, a secondary one and sometimes a third. It needs width, so it belongs to regular windows and collapses to one pane on a phone. Apple: Split view. Material 3: List-detail layout, by window size class. Appetite UI: Size class modes. ## Surfaces and states - **[Bottom sheet](https://www.appetiteui.com/glossary/bottom-sheet)**: A bottom sheet is a surface that slides up over the screen for a task related to it, and slides away when the task is done. Apple calls it a sheet. Apple: Sheet. Material 3: Bottom sheet. Appetite UI: Modal Sheet. - **[Action sheet](https://www.appetiteui.com/glossary/action-sheet)**: An action sheet lists the actions for one object at the bottom of the screen, with Cancel set apart. Material 3 has no action sheet and uses a modal bottom sheet for the same job. Apple: Action sheet. Material 3: Modal bottom sheet or menu. Appetite UI: Action Sheet. - **[Toast and snackbar](https://www.appetiteui.com/glossary/toast-snackbar)**: A toast or snackbar reports what just happened in a short message that leaves on its own and does not block the screen. Material 3 calls it a snackbar and can add one action; iOS has no system toast. Apple: No system component. Material 3: Snackbar. Appetite UI: Toast. - **[Liquid Glass](https://www.appetiteui.com/glossary/liquid-glass)**: Liquid Glass is the translucent material Apple introduced with iOS 26 for bars, buttons and sheets that float over content. Material 3 has no equivalent. Apple: Liquid Glass. Material 3: No equivalent. Appetite UI: liquidGlass effect styles. - **[Dynamic Island](https://www.appetiteui.com/glossary/dynamic-island)**: The Dynamic Island is the black pill around the iPhone’s front camera that grows to show live information, such as a timer, a delivery or a call. A Live Activity is what an app shows in it and on the Lock Screen. Apple: Dynamic Island and Live Activities. Material 3: No equivalent. Appetite UI: iOS / Dynamic Island, with System and Expanded sets. - **[Empty state](https://www.appetiteui.com/glossary/empty-state)**: An empty state is what a screen shows when it has nothing to show yet: no trips, an empty cart, no messages. A good one names what is missing and offers the action that fills it. Apple: Content unavailable view. Material 3: No component; covered in the guidelines. Appetite UI: Empty State. - **[Skeleton screen](https://www.appetiteui.com/glossary/skeleton-screen)**: A skeleton screen holds the shape of content while it loads, as grey lines, circles and blocks with a slow pulse, so the layout does not jump when the content arrives. Apple: Redacted placeholder in SwiftUI, no Figma component. Material 3: No component; progress indicators only. Appetite UI: Skeleton. - **[Alert dialog](https://www.appetiteui.com/glossary/alert-dialog)**: An alert dialog is a small modal window that interrupts a mobile screen to report a problem or ask for a decision. iOS calls it an Alert and Material 3 calls it a Dialog. Apple: Alert. Material 3: Dialog: basic, list and scrollable list. Appetite UI: Alert and Modal. - **[Context menu](https://www.appetiteui.com/glossary/context-menu)**: A context menu is a short list of actions that appears for the item a person touches and holds. iOS calls it a context menu, and Material 3 calls a similar list a dropdown menu. Apple: Context menu and Menu. Material 3: Dropdown menu. Appetite UI: Context Menu. - **[Progress indicator](https://www.appetiteui.com/glossary/progress-indicator)**: A progress indicator shows that a task is running, as a bar, a ring or a spinner. Apple calls the spinner an activity indicator, and Material 3 calls the family progress indicators. Apple: Progress view and activity indicator. Material 3: Linear and circular progress indicator. Appetite UI: Spinner, Progress Bar and Progress Ring. - **[Elevation](https://www.appetiteui.com/glossary/elevation)**: Elevation is the distance at which a surface sits above another, drawn as a shadow, a tint or a material. Material 3 sets it in dp levels, and iOS has no named shadow ramp. Apple: No named ramp: materials and depth. Material 3: Elevation levels. Appetite UI: dropShadow/xs to 2xl. - **[Onboarding](https://www.appetiteui.com/glossary/onboarding)**: Onboarding is the first-run flow that takes a person from opening a mobile app to using it, through a welcome, a sign-in and any setup. Apple asks for a flow that is fast, fun and optional. Apple: Onboarding. Material 3: No component: guidance only. Appetite UI: Welcome, Sign in and Sign up screens. - **[Tooltip](https://www.appetiteui.com/glossary/tooltip)**: A tooltip is a short label that explains a control, shown when it is pointed at or long-pressed. Material 3 has plain and rich tooltips, and Apple shows tooltips only in macOS and visionOS. Apple: No tooltip on iPhone: help tags in macOS and visionOS. Material 3: Plain tooltip and rich tooltip. Appetite UI: Tooltip. - **[Sheet detents](https://www.appetiteui.com/glossary/sheet-detents)**: Sheet detents are the heights at which a sheet comes to rest. iOS sheets have a large detent and an optional medium detent, and Material 3 bottom sheets are standard or modal. Apple: Sheet with medium and large detents. Material 3: Bottom sheet, standard and modal. Appetite UI: Modal Sheet. - **[Focus ring](https://www.appetiteui.com/glossary/focus-ring)**: A focus ring marks the control that has keyboard or switch focus. iPadOS and macOS draw a ring around it, and Material 3 tints the control with a focus state layer. Apple: System focus ring. Material 3: Focus state layer. Appetite UI: focusRing/brand and focusRing/error. - **[Permission request](https://www.appetiteui.com/glossary/permission-request)**: A permission request is the system alert that asks for access to data or a device feature, such as the camera or location. Both platforms ask the design to request it only when the feature needs it. Apple: Requesting permission, with a purpose description. Material 3: Runtime permissions, requested in context. Appetite UI: Permission Alert, Alert and Modal. - **[Passkey](https://www.appetiteui.com/glossary/passkey)**: A passkey is a credential stored on the device that replaces a password, unlocked with Face ID, a fingerprint or a screen lock. People give only a user name, and nothing typed can be phished. Apple: Passkeys, sign in with Face ID or Touch ID. Material 3: Credential Manager with passkeys. Appetite UI: Passkey. - **[Sign-in screen](https://www.appetiteui.com/glossary/sign-in-screen)**: A sign-in screen is where an app asks who someone is. Apple asks to require an account only when the core function needs one, and to delay the request until people have seen what the app does. Apple: Managing accounts: Sign in with Apple, passkeys. Material 3: Credential Manager sign-in. Appetite UI: Sign in and Sign up screens. - **[Review prompt](https://www.appetiteui.com/glossary/review-prompt)**: A review prompt is the dialog that asks for an App Store rating inside the app. Apple prefers the system prompt, which asks for a rating and an optional review and limits itself to three a year. Apple: Ratings and reviews, system prompt. Material 3: Google Play in-app review. Appetite UI: Review Prompt. - **[App icon](https://www.appetiteui.com/glossary/app-icon)**: An app icon is the image that stands for an app on the home screen, in search and in settings. Both platforms build it from a background and foreground layers, and the system applies the mask and the effects. Apple: App icon, layered with Liquid Glass attributes. Material 3: Adaptive icon: foreground and background layers. Appetite UI: Not drawn. - **[Launch screen](https://www.appetiteui.com/glossary/launch-screen)**: A launch screen is what the system shows from the moment an app starts until its first screen is ready. Apple asks to launch instantly and to use it to give the impression of speed, not to advertise. Apple: Launch screen, shown by the system. Material 3: Splash screen API. Appetite UI: Not drawn. - **[Widget](https://www.appetiteui.com/glossary/widget)**: A widget is a small view of an app that lives on the home screen or lock screen and shows timely, glanceable content. Some widgets carry interactive elements. Apple: Widgets: system families and accessory widgets. Material 3: App widgets. Appetite UI: Not drawn. - **[Haptic feedback](https://www.appetiteui.com/glossary/haptic-feedback)**: Haptic feedback is a tap, tick or vibration the device plays in answer to a touch. iOS plays it for switches, sliders and pickers on its own, and Android offers APIs for adding it to events. Apple: Playing haptics. Material 3: Haptic feedback, Android haptics APIs. Appetite UI: Not drawn. - **[Push notification](https://www.appetiteui.com/glossary/push-notification)**: A push notification is a message an app sends outside itself, shown as a banner or on the lock screen. It is brief, and Apple warns it should not be the only way to deliver critical information. Apple: Notifications: short look and long look. Material 3: Notifications. Appetite UI: Not drawn.