When we think about “using a computer,” we usually think in terms of graphical user interfaces, or GUIs: interfaces (like Microsoft Word, the Mac OS, or the WordPress admin interface) that are specially and attractively designed, that have programs and windows and tabs that visibly open and close, and that let you click things and drag things and drop things and hover things. For some development tasks, the command line is still both significantly faster and more powerful than any GUI tool.
It wasn’t always this way. The original manner of interacting with a computer is through the terminal, also called the command line: a stripped-down, usually mouse-free interface for entering programming commands directly.
Well, the terminal’s not just a piece of history. For some kinds of tasks, the command line is still both significantly faster to use and more powerful than any GUI tool that exists. This is especially true for a WordPress developer, thanks to one of the coolest pieces of programming ever to hit the WordPress community: the WP-CLI project, which hugely simplifies all kinds of WordPress tasks—everything from “delete the 100 oldest comments”