adb
is a command line tool for communicating with an emulator instance or connected device. It allows for installing and debugging apps, transferring files, as well as a variety of other interactions with the connected emulator or device. The ADB system consists of a client, which sends commands from the host computer, a daemon, which runs on the connected device and executes commands received from the client, and a server, which runs on the host computer and manages communications between the client and daemon.
Official Documentation
https://developer.android.com/studio/command-line/adb.html