The Android Debug Bridge (ADB) is a versatile command-line tool used for debugging Android-based devices. It facilitates a variety of device actions, such as installing and debugging apps, providing access to a Unix shell, and running various commands on a device. ADB is a client-server program that includes three components: a client, which sends commands; a daemon (adbd), which runs commands on a device; and a server, which manages communication between the client and the daemon. ADB is compatible with Windows, Linux, and macOS, and it is included in the Android SDK Platform Tools package. It can be used to install standalone APKs, move files between a computer and a device, run shell commands, take screenshots, view system logs, and more. ADB is a powerful tool for Android developers and power users, enabling them to send commands to control device behavior.