File system layout describes how an operating system organizes files, folders, devices, and user data. Students need this reference to understand paths, directory trees, permissions, and where important files usually belong. This cheat sheet helps connect programming, operating systems, command-line work, and cybersecurity basics.
It is especially useful when navigating Linux, macOS, Windows, or project folders.
Key Facts
- A file system is a method an operating system uses to name, store, organize, and retrieve files on a storage device.
- A directory tree starts at a root location, such as / on Linux and macOS or C:\ on Windows.
- An absolute path gives the full location from the root, such as /home/ana/report.txt or C:\Users\Ana\report.txt.
- A relative path gives a location from the current working directory, such as ../images/logo.png.
- The symbol . means the current directory, and .. means the parent directory one level above.
- Typical Linux folders include /home for users, /etc for configuration, /bin for essential programs, /var for changing data, and /tmp for temporary files.
- File permissions usually control read, write, and execute access for the owner, group, and others.
- A good project layout separates source code, tests, data, documentation, and build output into clearly named folders.
Vocabulary
- Root directory
- The top-level directory from which all other files and folders branch.
- Path
- A text address that identifies where a file or folder is located in a file system.
- Absolute path
- A complete path that starts at the root location and uniquely identifies a file or folder.
- Relative path
- A path written from the current working directory instead of from the root.
- Mount point
- A directory where another storage device or file system is attached and accessed.
- Permission
- A rule that determines who can read, modify, or execute a file or folder.
Common Mistakes to Avoid
- Confusing absolute and relative paths is wrong because an absolute path starts at the root, while a relative path depends on the current working directory.
- Using the wrong path separator is wrong because Windows commonly uses backslashes like C:\Users\Ana, while Linux and macOS use forward slashes like /home/ana.
- Deleting or editing system folders without understanding them is dangerous because folders such as /etc, /bin, C:\Windows, and Program Files contain files needed by the operating system.
- Assuming file extensions always prove file type is wrong because extensions are naming conventions, while the file contents and metadata may tell a different story.
- Giving everyone write or execute permission is unsafe because it can allow accidental changes, malware execution, or unauthorized access.
Practice Questions
- 1 In the path /home/student/projects/app/main.py, what is the root directory, and what is the file name?
- 2 If your current directory is /home/student/projects and a file is stored at /home/student/images/logo.png, write a relative path to the file.
- 3 A Windows file is located at C:\Users\Maya\Documents\essay.docx. Identify the drive, two folders, and the file name.
- 4 Why is it useful for an operating system to separate user files, system files, configuration files, and temporary files into different folders?