Upendra 
Service vs IntentService
A Service is an application component that can perform long-running operations in the background, and it doesn’t provide a user interface. Another application component can start a service, and it continues to run in the background even if the user switches to another application. Additionally, a component can bind to a service to interact with it and even perform interprocess communication (IPC).
The Service class is the base class for all services. When you extend this class, it’s important to create a new thread in which the service can complete all of its work; the service uses your application’s main thread by default, which can slow the performance of any activity that your application is running.
The Android framework also provides the IntentService subclass of Service that uses a worker thread to handle all of the start requests, one at a time. IntentService is very similura to queue where it handles request (intents) from clients. Client can send the request to IntentService by using command - Context.startService(Intent). For implements IntentService you should extend IntentService class and implements method - onHandleIntent(Intent)
Using IntentService is not recommended for new apps as it will not work well starting with Android 8 Oreo, due to the introduction of Background execution limits. Moreover, it’s deprecated starting with Android 11. You can use JobIntentService as a replacement for IntentService that is compatible with newer versions of Android.
Service |
IntentService |
|---|---|
Is invoked using startService() |
Is invoked using Intent |
| Can be invoked from any thread | Can in invoked from the Main thread only |
| Runs background operations on the Main Thread of the Application by default. Hence it can block your Application’s UI | Creates a separate worker thread to run background operations |
| Invoked multiple times would create multiple instances. | Invoked multiple times won’t create multiple instances |
Needs to be stopped using stopSelf() or stopService() |
Automatically stops after the queue is completed. No need to trigger stopService() or stopSelf() |
| Can run parallel operations | Multiple intent calls are automatically queued and they would be executed sequentially |
Links
https://developer.android.com/guide/components/services
https://www.journaldev.com/20735/android-intentservice-broadcastreceiver
https://stackoverflow.com/questions/15524280/service-vs-intentservice-in-the-android-platform
