Your files are a tree, and you're standing in it

To move around in the terminal, you need a picture of what you're moving around in. Here it is.

Your files are arranged as a tree. A folder holds files and other folders, and those folders hold more files and folders, all the way down. You've seen this a thousand times in your file window. The terminal uses the exact same tree.

home
├── Desktop
├── Documents
│   ├── taxes
│   └── resume.pdf
└── Downloads

The one new idea: in the terminal, you are always standing in one folder. Not looking at all of them. Standing in exactly one. That folder is called your current directory ("directory" is just the old word for folder, and the terminal uses it constantly).

Every command you run happens from where you're standing. ls shows what's in the folder you're in. mkdir makes a folder inside the one you're in. Moving around means changing which folder you're standing in.

Two shortcuts worth knowing now

These two symbols show up everywhere:

• ~ means your home folder. The top of your personal tree, where Desktop, Documents, and Downloads live. When a terminal opens, it usually starts you at ~.
• .. means the folder one level up. The parent of where you're standing. If you're in Documents/taxes and you go .., you land in Documents.

That's the model. You're standing somewhere in a tree. Commands act on where you stand. ~ is home, .. is up. The next three steps are just the commands for looking around and stepping between folders.