A service is bound when an application component binds to it by
calling bindService(). A bound service offers a client-server
interface that allows components to interact with the service, send
requests, get results, and even do so across processes with
interprocess communication (IPC).When the last client unbinds from the service, the system destroys the
service EXCEPT If the service was started by
startService
Unbound Service or Started
A service is started when an application component, such as an
activity, starts it by calling startService(). Once started, a service
can run in the background indefinitely, even if the component that
started it is destroyed.
BUT
Most confusion about the Service class actually revolves around what it is not:
A Service is not a separate process. The Service object itself does
not imply it is running in its own process; unless otherwise
specified, it runs in the same process as the application it is part
of.A Service is not a thread. It is not a means itself to do work off of
the main thread (to avoid Application Not Responding errors).
That is where IntentService are used.
IntentService is a subclass of Service that uses a worker thread to
handle all start asynchronous requests (expressed as Intents) on
demand, one at a time. Clients send requests through
startService(Intent) calls; the service is started as needed, handles
each Intent in turn using a worker thread, and stops itself when it
runs out of work.
hope it helps 🙂