feat(mobile): Explain how sessions work for session replay (#14663)

Author: romtsn

docs/platforms/android/session-replay/index.mdx

@@ -71,6 +71,16 @@ While you're testing, we recommend that you set `sessionSampleRate` to `1.0`. Th
 
 Once testing is complete, **we recommend lowering this value in production**. We still recommend keeping `onErrorSampleRate` set to `1.0`.
 
+## User Session
+
+A user session starts when the Sentry SDK is initialized or when the application enters the foreground. The session will capture screen transitions, navigations, touches and other events until the application is sent to the background. If the application is brought back to the foreground within 30 seconds (default), the same `replay_id` will be used and the session will continue.
+
+The session will be terminated if the application has spent in the background more than 30 seconds or when the maximum duration of 60 minutes is reached. You can adjust the [session tracking interval](/platforms/android/configuration/releases/#sessions) to extend or shorten the duration of a single replay, depending on your needs.
+
+### Replay Captures on Errors Only
+
+If you prefer not to record an entire session, you can elect to capture a replay only if an error occurs. In this case, the integration will buffer up to one minute worth of events prior to the error being thrown. It will continue to record the session, following the rules above regarding session life and activity. Read the [sampling](#sampling) section for configuration options.
+
 ## Sampling
 
 Sampling allows you to control how much of your website's traffic will result in a Session Replay. There are two sample rates you can adjust to get the replays relevant to you:

docs/platforms/apple/guides/ios/session-replay/index.mdx

@@ -56,6 +56,16 @@ While you're testing, we recommend that you set `sessionSampleRate` to `1.0`. Th
 
 Once testing is complete, **we recommend lowering this value in production**. We still recommend keeping `onErrorSampleRate` set to `1.0`.
 
+## User Session
+
+A user session starts when the Sentry SDK is initialized or when the application enters the foreground. The session will capture screen transitions, navigations, touches and other events until the application is sent to the background. If the application is brought back to the foreground within 30 seconds (default), the same `replay_id` will be used and the session will continue.
+
+The session will be terminated if the application has spent in the background more than 30 seconds or when the maximum duration of 60 minutes is reached. You can adjust the [session tracking interval](/platforms/apple/guides/ios/configuration/releases/#sessions) to extend or shorten the duration of a single replay, depending on your needs.
+
+### Replay Captures on Errors Only
+
+If you prefer not to record an entire session, you can elect to capture a replay only if an error occurs. In this case, the integration will buffer up to one minute worth of events prior to the error being thrown. It will continue to record the session, following the rules above regarding session life and activity. Read the [sampling](#sampling) section for configuration options.
+
 ## Sampling
 
 Sampling allows you to control how much of your app's traffic will result in a Session Replay. There are two sample rates you can adjust to get the replays relevant to you:

docs/platforms/dart/guides/flutter/session-replay/index.mdx

@@ -51,6 +51,16 @@ While you're testing, we recommend that you set `sessionSampleRate` to `1.0`. Th
 
 Once testing is complete, **we recommend lowering this value in production**. We still recommend keeping `onErrorSampleRate` set to `1.0`.
 
+## User Session
+
+A user session starts when the Sentry SDK is initialized or when the application enters the foreground. The session will capture screen transitions, navigations, touches and other events until the application is sent to the background. If the application is brought back to the foreground within 30 seconds (default), the same `replay_id` will be used and the session will continue.
+
+The session will be terminated if the application has spent in the background more than 30 seconds or when the maximum duration of 60 minutes is reached. You can adjust the [session tracking interval](/platforms/dart/guides/flutter/configuration/releases/#sessions) to extend or shorten the duration of a single replay, depending on your needs.
+
+### Replay Captures on Errors Only
+
+If you prefer not to record an entire session, you can elect to capture a replay only if an error occurs. In this case, the integration will buffer up to one minute worth of events prior to the error being thrown. It will continue to record the session, following the rules above regarding session life and activity. Read the [sampling](#sampling) section for configuration options.
+
 ## Sampling
 
 Sampling allows you to control how much of your website's traffic will result in a Session Replay. There are two sample rates you can adjust to get the replays relevant to you:

docs/platforms/react-native/session-replay/index.mdx

@@ -69,6 +69,16 @@ While you're testing, we recommend that you set <PlatformIdentifier name="replay
 
 Once testing is complete, **we recommend lowering this value in production**. We still recommend keeping <PlatformIdentifier name="replays-on-error-sample-rate" /> set to `1.0`.
 
+## User Session
+
+A user session starts when the Sentry SDK is initialized or when the application enters the foreground. The session will capture screen transitions, navigations, touches and other events until the application is sent to the background. If the application is brought back to the foreground within 30 seconds (default), the same `replay_id` will be used and the session will continue.
+
+The session will be terminated if the application has spent in the background more than 30 seconds or when the maximum duration of 60 minutes is reached. You can adjust the [session tracking interval](/platforms/react-native/configuration/releases/#sessions) to extend or shorten the duration of a single replay, depending on your needs.
+
+### Replay Captures on Errors Only
+
+If you prefer not to record an entire session, you can elect to capture a replay only if an error occurs. In this case, the integration will buffer up to one minute worth of events prior to the error being thrown. It will continue to record the session, following the rules above regarding session life and activity. Read the [sampling](#sampling) section for configuration options.
+
 ## Sampling
 
 Sampling allows you to control how much of your website's traffic will result in a Session Replay. There are two sample rates you can adjust to get the replays relevant to you: