"Bash" stands for "Bourne Again Shell". It's a Unix shell, which is a command-line interface for interacting with an operating system. Bash is widely used as the default shell on many Linux distributions, as well as macOS. It provides a number of built-in commands and allows users to combine those commands in various ways to automate tasks and perform complex operations. Additionally, Bash also supports scripting, which enables users to write scripts that automate tasks and execute a series of commands in sequence.