The daemon runs as a background process on each device.
You can invoke a client from a command-line terminal by issuing an adb command. The client runs on your development machine. It is a client-server program that includes three components: The adb command facilitates a variety of device actions, such as installing and debugging apps, and it provides access to a Unix shell that you can use to run a variety of commands on a device. “Android Debug Bridge (adb) is a versatile command-line tool that lets you communicate with a device (an emulator or a connected Android device).
