Android Debug Bridge (ADB) is a versatile command-line tool that enables communication between a computer and an Android device. Primarily used by developers, ADB allows for installing and debugging apps, transferring files, and issuing commands directly to the device. While it is essential for development and troubleshooting, ADB can also pose security risks if left enabled on devices, as attackers may exploit it to gain unauthorized access, install malicious apps, or extract sensitive data. Proper configuration and disabling ADB when not in use are crucial for maintaining device security.