It is a "run control" file that originated with Bash (Bourne Again Shell), the most popular and widely used Linux shell.

Most Linux systems use Bash (Bourne Again SHell) as the default shell—because it’s versatile and sufficient for casual use. However, there are other shells available, like Zsh, Ksh ...

Typically we interact with the Linux operating system through what is referred to as a shell interpreter. A common interpreter is the Bourne Again Shell, which people call by the catchy name of bash ...