File System Navigation

What Is a File System?

A file system is how your operating system:

• Stores files
• Organizes folders
• Keeps track of locations on disk

Think of it like a tree structure.

Example:

Root
 ├── Users
 │    ├── Alice
 │    │     └── notes.txt
 │    └── Bob
 └── Program Files

Everything starts from a top-level directory called the root.

• Windows root example: C:\
• Linux/macOS root: /

Key Terms You Must Understand

Directory = Folder

File = Document or program

Path = The location of a file or folder

Example path (Windows):

C:\Users\John\Documents\file.txt

Example path (Linux/macOS):

/home/john/Documents/file.txt

A path tells the system exactly where something is located.

Absolute vs Relative Paths

Absolute Path

Starts from the root.

Examples:

Windows:

C:\Users\John\Documents

Linux/macOS:

/home/john/Documents

Relative Path

Starts from your current location.

Example:

Documents

If you are already inside /home/john, then Documents means:

/home/john/Documents

Viewing Where You Are

Linux/macOS:

pwd

This means: Print Working Directory.

Windows (Command Prompt):

cd

It shows your current location.

Listing Files and Folders

Linux/macOS:

ls

Windows:

dir

These commands show what is inside your current folder.

Moving Between Folders

The most important command is:

cd

cd = change directory

Move Into a Folder

Linux/macOS:

cd Documents

Windows:

cd Documents

Move Back One Level

cd ..

The two dots .. mean "go up one folder."

Move to Root

Linux/macOS:

cd /

Windows:

cd \

Move to Home Directory (Linux/macOS)

cd ~

The ~ symbol means your home folder.

Special Navigation Symbols

. = Current directory

.. = Parent directory

~ = Home directory (Linux/macOS)

Example:

cd ../..

This moves up two levels.

Tab Auto-Completion

In most terminals, you can press the TAB key to auto-complete folder names.

Example:

If you type:

cd Doc

Then press TAB, it may complete to:

cd Documents

This saves time and prevents mistakes.

Example Navigation Session (Linux/macOS)

pwd
ls
cd Documents
ls
cd ..
cd /
pwd

Example Navigation Session (Windows)

cd
dir
cd Documents
dir
cd ..
cd \
cd

How the System Actually Handles Navigation

When you type:

cd Documents

The operating system:

1. Checks if the folder exists
2. Checks if you have permission
3. Changes your working directory
4. Updates the prompt

Your files are not moving. Only your location changes.

Think of it like walking inside a building. The building stays the same, but your position changes.