Files, folders, metadata and file systems

The OS as a librarian

The OS also stores and organizes your data. It does this through the file system: a structured way to store, find and manage information on storage devices. It keeps data organized, secure and easy to retrieve, even with thousands of files.

A file is a collection of related data: text, images, audio, video or program instructions. A folder, also called a directory, is a container that organizes files and other folders so information is easier to find.

Metadata is information about a file or folder: its name, type, size, date of creation and date of last change. It lets you and the OS identify and manage files without opening them.

A file system is the way the OS stores and organizes files on a hard drive, SSD or USB. It decides where each file goes and saves its location. Like a librarian, it puts your photo in the right place and knows where to find it again.

Your book lists FAT32 for USB flash drives, NTFS for Windows, APFS or HFS+ for macOS, and ext4 for Linux. The choice affects performance, storage capacity and security.

File = the data. Folder = the container. Metadata = data about the file. File system = the OS's rules for where files live and how they are found.

Key terms

File

Holding text, images, audio, video or program instructions.

Folder

Organizing files and other folders.

Metadata

Identifying and managing files without opening them.

File system

Deciding where each file is kept and remembering its location.

Short questions with model answers

1. Q1. Short Question 9 (p. 17): what is the role of a file system?

   • Say what it does.
   • Say how.

   It is how the OS stores and organizes files, deciding where each is kept and remembering where to find it, like a librarian.

2. Q2. You copy a song from a Windows laptop to a USB flash drive. Which file systems does your book link to each?

   • Windows: NTFS.
   • USB flash drive: FAT32.

   The laptop uses NTFS and the flash drive FAT32; each OS still keeps the song's metadata (name, type, size, dates).

Common mistakes

• ✗ Saying metadata is the content inside the file.

  ✓ Metadata is details about the file (name, type, size, dates), read without opening it.

• ✗ Calling a folder a file.

  ✓ A folder (directory) is a container that holds files and other folders.

• ✗ Mixing up which OS uses which file system.

  ✓ NTFS Windows, APFS or HFS+ macOS, ext4 Linux, FAT32 USB flash drives.

MCQs

1. 1. Which file system does your book say Windows uses?

   1. (a) ext4
   2. (b) APFS
   3. (c) NTFS
   4. (d) HFS+
   Show answer

   (c) 1.7.4, p. 13.

2. 2. A file's size and date of last modification are its:

   1. (a) Metadata
   2. (b) Folder
   3. (c) System call
   4. (d) Driver
   Show answer

   (a) 1.7.3, p. 13.

3. 3. Another name for a folder is a:

   1. (a) Kernel
   2. (b) Directory
   3. (c) Thread
   4. (d) Partition
   Show answer

   (b) 1.7.2, p. 13.

4. 4. Which file system does your book link to USB flash drives?

   1. (a) NTFS
   2. (b) ext4
   3. (c) APFS
   4. (d) FAT32
   Show answer

   (d) 1.7.4, p. 13.

5. 5. What does the choice of file system affect, according to your book?

   1. (a) Only the colour of icons
   2. (b) The keyboard layout
   3. (c) Performance, storage capacity and security
   4. (d) The number of users
   Show answer

   (c) 1.7.4, p. 13.

Quick revision

• A file is related data; a folder (directory) organizes files and other folders.
• Metadata (name, type, size, dates) lets you manage files without opening them.
• A file system decides where files go and remembers their location: FAT32, NTFS, APFS/HFS+, ext4.