Bash is useful when working on Google Cloud, mainly with Compute Engine. In Bash, you can create functions and run if statements almost like an object oriented language, and it runs in a terminal. Bash can be useful for running installs or automating things on your OS. I have messed around with building a small script written in bash, to automate a common ubuntu setup.
Bash is a Unix shell and command language written by Brian Fox for the GNU Project as a free software replacement for the Bourne shell. First released in 1989, it has been used as the default login shell for most Linux distributions. A version is also available for Windows 10 via the Windows Subsystem for Linux. It is also the default user shell in Solaris 11. Bash was also the default shell in all versions of Apple macOS prior to the 2019 release of macOS Catalina, which changed the default shell to zsh, although Bash currently remains available as an alternative shell.