The specified string constant is a system-defined action that signals a change in the device’s screen state. Specifically, it indicates that the screen has been turned on. A broadcast receiver can be configured to listen for this action, allowing an application to execute code when the user activates the device’s display. For instance, an application might use this signal to resume playing media or refresh data presented on the screen.
This signal is valuable for applications requiring awareness of the device’s power state and user activity. Knowing when the screen is active enables efficient resource management, preventing unnecessary background processing while the device is idle and optimizing performance when the user is actively engaging with it. Its use case has evolved since the early versions of Android, becoming crucial for power-saving and context-aware application behavior.