File Systems and Folder Structures
Every file on your computer has a place. The file system is the structure that organizes all your data — documents, applications, system files — into a navigable hierarchy. Understanding this structure helps you find files, organize projects, and work effectively with code.
The Tree Structure
File systems are organized like trees (or more accurately, like upside-down trees). At the top is a single starting point called the root. From there, folders branch out, and those folders contain more folders or files. This hierarchical structure lets you organize millions of files in a logical way.
Think of it as a giant filing cabinet. The cabinet itself is the root. Each drawer is a top-level folder. Inside drawers are hanging folders, and inside those are individual documents. You can nest organization as deep as you need.
Root Directories Across Systems
Different operating systems name their roots differently:
Unix-like systems (macOS and Linux) use a single forward slash / as the root. Everything branches from there: /Users, /Applications, /etc.
Windows uses drive letters with backslashes. The primary drive is typically C:\, with folders like C:\Users, C:\Program Files, C:\Windows.
Home Directories
Every user has a home directory — a personal space for their files and settings.
On macOS: /Users/yourname
On Linux: /home/yourname
On Windows: C:\Users\yourname
Your documents, downloads, and application settings typically live within your home directory.
Paths: Addresses for Files
A path is the complete address to a file or folder. It describes exactly where something lives in the hierarchy.
Absolute paths start from the root and specify the complete location: /Users/alex/Documents/project/readme.txt
Relative paths describe location relative to where you currently are. If you're in /Users/alex, then Documents/project refers to /Users/alex/Documents/project.
System vs User Folders
Operating systems separate system files from user files. System folders contain the OS itself and installed applications. User folders contain personal data. This separation protects the system — you can freely modify your documents without risking system stability.