# iOS
- [iOS Attributes](#ios-attributes)
- [Deprecated iOS Attributes](#deprecated-ios-attributes)
## iOS Attributes
This group describes iOS-specific attributes.
| Attribute | Type | Description | Examples | Stability |
|---|---|---|---|---|
| `ios.app.state` | string | This attribute represents the state of the application. [1] | `active`; `inactive`; `background` |  |
**[1] `ios.app.state`:** The iOS lifecycle states are defined in the [UIApplicationDelegate documentation](https://developer.apple.com/documentation/uikit/uiapplicationdelegate), and from which the `OS terminology` column values are derived.
---
`ios.app.state` has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.
| Value | Description | Stability |
|---|---|---|
| `active` | The app has become `active`. Associated with UIKit notification `applicationDidBecomeActive`. |  |
| `background` | The app is now in the background. This value is associated with UIKit notification `applicationDidEnterBackground`. |  |
| `foreground` | The app is now in the foreground. This value is associated with UIKit notification `applicationWillEnterForeground`. |  |
| `inactive` | The app is now `inactive`. Associated with UIKit notification `applicationWillResignActive`. |  |
| `terminate` | The app is about to terminate. Associated with UIKit notification `applicationWillTerminate`. |  |
## Deprecated iOS Attributes
The iOS platform on which the iOS application is running.
| Attribute | Type | Description | Examples | Stability |
|---|---|---|---|---|
| `ios.state` | string | [2] | `active`; `inactive`; `background` | 
Replaced by the `ios.app.state` event body field. |
**[2] `ios.state`:** The iOS lifecycle states are defined in the [UIApplicationDelegate documentation](https://developer.apple.com/documentation/uikit/uiapplicationdelegate), and from which the `OS terminology` column values are derived.
---
`ios.state` has the following list of well-known values. If one of them applies, then the respective value MUST be used; otherwise, a custom value MAY be used.
| Value | Description | Stability |
|---|---|---|
| `active` | The app has become `active`. Associated with UIKit notification `applicationDidBecomeActive`. |  |
| `background` | The app is now in the background. This value is associated with UIKit notification `applicationDidEnterBackground`. |  |
| `foreground` | The app is now in the foreground. This value is associated with UIKit notification `applicationWillEnterForeground`. |  |
| `inactive` | The app is now `inactive`. Associated with UIKit notification `applicationWillResignActive`. |  |
| `terminate` | The app is about to terminate. Associated with UIKit notification `applicationWillTerminate`. |  |