1# UIAbility Overview 2 3 4## Overview 5 6UIAbility is a type of application component that provides the UI for user interactions. 7 8The following design philosophy is behind UIAbility: 9 101. Native support for [cross-device migration](hop-cross-device-migration.md) and [multi-device collaboration](hop-multi-device-collaboration.md) at the application component level 11 122. Support for multiple device types and window modes 13 14> **NOTE** 15> 16> For details, see [Interpretation of the Application Model](application-model-description.md). 17 18UIAbility is the basic unit of scheduling in OpenHarmony and provides a window for applications to draw the UI. An application can contain one or more UIAbility components. For example, for a payment application, you can use separate UIAbility components to carry the entry and payment functionalities. 19 20Each UIAbility component instance is displayed as a mission in the system application Recents. 21 22You can develop a single UIAbility or multiple UIAbilities for your application based on service requirements. 23 24- If you want your application to be displayed as one mission in Recents, use one UIAbility and multiple pages. 25 26- If you want your application to be displayed as multiple missions in Recents or multiple windows to be opened simultaneously, use multiple UIAbilities. 27 28## Declaration Configuration 29 30To enable an application to properly use a UIAbility component, declare the UIAbility name, entry, and label under [abilities](../quick-start/module-configuration-file.md#abilities) in the [module.json5 file](../quick-start/module-configuration-file.md). 31 32 33```json 34{ 35 "module": { 36 ... 37 "abilities": [ 38 { 39 "name": "EntryAbility", // Name of the UIAbility component. 40 "srcEntry": "./ets/entryability/EntryAbility.ts", // Code path of the UIAbility component. 41 "description": "$string:EntryAbility_desc", // Description of the UIAbility component. 42 "icon": "$media:icon", // Icon of the UIAbility component. 43 "label": "$string:EntryAbility_label", // Label of the UIAbility component. 44 "startWindowIcon": "$media:icon", // Index of the icon resource file. 45 "startWindowBackground": "$color:start_window_background", // Index of the background color resource file. 46 ... 47 } 48 ] 49 } 50} 51``` 52