What is a default interactive shell and why did I get an automated message about it?

Opened my MacBook Pro OS Sequoia 15.6.1 one morning and the terminal was running. It sent me to a link to "Use ZSH as the default shell." Use zsh as the default shell on your Mac - Apple SupportB


ut I can't find the Apple Glossary (please tell me there is one!) that will tell me what a default shell is or why I would use one. For all I know, it's a raincoat. Help.



MacBook Pro 16″, macOS 15.6

Posted on Aug 26, 2025 01:49 PM

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1 reply

Aug 26, 2025 02:47 PM in response to Lauraald4

This is a normal terminal message


For the apple article see this Change the default shell in Terminal on Mac - Apple Support



And here for a quick exlpanation about what the shell is


On a Mac, a shell is a program that provides a command-line interface (CLI) between you (the user) and the operating system. Instead of clicking through menus and windows, you type text commands that the shell interprets and sends to the underlying system (macOS, which is based on Unix).


Here’s the breakdown:

  • The role of the shell
  • It’s a command interpreter: you type a command, and the shell runs it.
  • It acts as a middle layer between you and the kernel (the core of macOS).
    • It lets you run programs, navigate the file system, manage processes, and automate tasks with scripts.



What is a default interactive shell and why did I get an automated message about it?

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