Linux Basic — The Linux File System

The Linux File System

Everything in Linux is a file. Configuration, devices, processes, and network sockets are all represented as files in a single unified directory tree. Understanding this tree — and how files work — is fundamental to Linux mastery.

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What You Will Learn

By the end of this chapter you will be able to:

• Navigate the Filesystem Hierarchy Standard (FHS) directory structure
• Explain the difference between absolute and relative paths
• Read and interpret ls -l file type characters
• Explain what an inode is and use stat to inspect one
• Understand hard links and symbolic links
• Use df and du to monitor disk space

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Topics in This Chapter

#	Topic	Description
1	FHS Directory Hierarchy	What each directory is for
2	Absolute vs Relative Paths	How Linux paths work
3	File Types and Inodes	What ls -l type characters mean
4	Hard Links and Symlinks	Two kinds of file links
5	Disk Usage: df and du	Monitor and analyse disk space
6	Practice Exercises	Hands-on tasks

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The Single-Root Tree

Unlike Windows (C:\, D:), Linux has a single root /:

/                        ← root of everything
├── bin/                 ← user commands
├── etc/                 ← configuration files
├── home/                ← user home directories
│   ├── ubuntu/
│   └── alice/
├── var/                 ← variable data (logs, databases, mail)
│   └── log/
└── tmp/                 ← temporary files

Every file on every disk appears somewhere in this tree. External drives, network shares, and USB sticks are all mounted as subdirectories.

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Next → FHS Directory Hierarchy