PATH
Domain: Computer Systems
🎯 Motivation
An environment variable listing directories where the OS looks for executable programs. Determines what commands work in the terminal.
📋 Concrete Example
PATH: /usr/bin:/usr/local/bin:/home/user/.local/bin. When you type python, the OS searches these directories for python. If found, it runs. If not: ‘command not found’.
🔗 Analogy
PATH is like a list of grocery stores you visit - you look for milk at Store A, then Store B, then Store C. The OS looks for programs in PATH directories, in order.