$ man bash

Bash

A shell language that interprets the commands you type in the terminal. Zsh is the modern Mac default and is Bash-compatible.

by Shawn Tenam

When you type a command in the terminal, Bash (or Zsh) is the program that interprets it and tells the computer what to do. Bash scripts automate sequences of commands. The .zshrc file configures your shell environment. Understanding that a shell exists between you and the computer explains why things like PATH and permissions work the way they do.

Mac uses Zsh by default but Bash scripts still work. Shell scripts start with #!/bin/bash or #!/bin/zsh. You write scripts to automate repeated command sequences. Most of the time you do not write shell scripts directly. You let Claude write them.