Software & Operating Systems

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File systems and file management

⏱ 4 min read🧩 6 question types🎯 15 practice Q

The idea in one minute

A file system is the set of rules an OS uses to name, store and find files on a disk. FAT32, exFAT and NTFS are the three most asked. FAT32 cannot hold a single file larger than 4 GB.

What a file system does

A file system is the OS's rulebook for a disk. It says how files are named, stored in folders, found again and protected. Formatting a drive writes this rulebook onto it.

File systems compared

File system	Used by	Key facts
FAT32	Windows 9x, pen drives	Single file up to 4 GB (minus 1 byte). No permissions, no journaling
exFAT	Flash drives, cameras	Removes the 4 GB file limit. Light and simple
NTFS	Modern Windows	Journaling, permissions, encryption, compression, huge files. Default for Windows
ext4	Linux	Journaling. Default on many distros
APFS	macOS and iOS	Snapshots and encryption

Full forms: FAT is File Allocation Table. NTFS is New Technology File System.

Rule: A file larger than 4 GB will not copy into a FAT32 drive. Use exFAT or NTFS.

Windows formats FAT32 volumes only up to about 32 GB. Journaling means the system keeps a log, so it can recover after a crash.

File names and extensions

A file name has two parts: name.extension, such as report.docx. The extension tells the OS which program opens the file.

Extension	File type	Extension	File type
.txt	Plain text	.docx	Word document
.xlsx	Excel workbook	.pptx	PowerPoint show
.pdf	Portable Document	.jpg / .png	Images
.mp3 / .wav	Audio	.mp4	Video
.zip	Compressed archive	.html	Web page
.exe	Executable program	.bat	Batch (command) file

Watch: A Windows file name cannot contain any of these: \ / : * ? " < > |

Wildcards in search

? stands for exactly one character. file?.txt finds file1.txt and fileA.txt.
* stands for any number of characters. *.pdf finds every PDF.

Tip: s?t finds sat, set and sit. *.docx finds all Word files.

Paths and file terms

File: a named collection of related data.
Folder (directory): a container for files.
Path: the address of a file, written drive:\folders\file.ext.
Attributes: read-only, hidden, archive and system.

Copy, move and delete

Copy (Ctrl+C, Ctrl+V) keeps the original and makes a duplicate.
Move (Ctrl+X, Ctrl+V) shifts the file. The original disappears.
Delete sends the file to the Recycle Bin. Shift+Delete skips the bin.
Properties (Alt+Enter) shows size, dates and the read-only switch.

Formatting prepares a disk with a file system. It erases the directory, but it does not physically shred the data.

Question types you will see

Each type: how to recognise it, the method step by step, and one question to try.

Type 1very common4 practice Q

FAT32, NTFS and exFAT limits

How to spot it:

Maximum file size on FAT32, the default Windows file system, or why a large file will not copy.

Method

Note the file size in the question.
Compare it to the FAT32 limit of 4 GB.
If it is larger, the answer is the FAT32 limit.

Why it works:

The 4 GB limit is the single most asked file system fact.

Try this

A 16 GB pen drive formatted as FAT32 refuses a 6 GB movie file. Why?

Show solution

6 GB is more than 4 GB.
FAT32 cannot store one file that large.
Reformat as exFAT or NTFS.

Answer

FAT32 cannot store a single file larger than 4 GB

Type 2very common4 practice Q

Wildcards in file search

How to spot it:

A pattern like *.pdf or file?.txt is given, and what it finds is asked.

Method

Read each symbol in the pattern.
? replaces exactly one character.
- replaces any number of characters.

Why it works:

The two symbols work differently, and the pattern decides the match.

Try this

In a Windows search, which name does file?.txt match?

Show solution

The name starts with file.
One character comes next.
Then .txt follows.

Answer

file1.txt or fileA.txt (exactly one character after file)

Type 3very common3 practice Q

Extension and file type

How to spot it:

An extension is given and its file type is asked, or a matching table is shown.

Method

Read the extension after the dot.
Match it to the extension table.
Check the column pairs.

Why it works:

The extension tells the OS which program opens the file.

Try this

The file extension .exe marks a file as

Show solution

The extension is .exe.
Double-clicking it runs the code.

Answer

An executable program

Type 4common2 practice Q

Formatting and disk housekeeping

How to spot it:

Formatting, defragmentation or disk cleanup is defined and the term is asked.

Method

Formatting lays down a file system.
Defragmenting joins scattered pieces.
Cleanup deletes junk and temporary files.

Why it works:

Each action does one different job on a disk.

Try this

Formatting a hard disk mainly

Show solution

It writes a file system onto the disk.
It does not enlarge the disk.

Answer

Prepares the disk with a file system so files can be stored and found

Type 5common

Copy, move and delete

How to spot it:

A question asks what happens to the original file, or which shortcut is used.

Method

Copy keeps the original.
Move removes the original.
Delete goes to the Recycle Bin. Shift+Delete skips it.

Why it works:

The fate of the original file separates the three actions.

Try this

After you cut a file and paste it into another folder, what happens to the original?

Show solution

Cut is Ctrl+X.
Paste places the file in the new folder.

Answer

The original disappears from the old folder

Type 6occasional

Illegal characters and paths

How to spot it:

A list of file names is given and the valid one is asked. Or a path is shown.

Method

Scan each name for \ / : * ? " < > |.
Cross out any name with these.
A path is written drive:\folder\file.ext.

Why it works:

Windows rejects names containing these nine characters.

Try this

Which of these is a valid Windows file name? (A) report:final.docx (B) report_final.docx (C) report*final.docx (D) report?final.docx

Show solution

A has a colon.
C has an asterisk.
D has a question mark.
B has none of the banned characters.

Answer

(B) report_final.docx

Shortcuts that save time

⚡ FAT32 four-GB wall

FAT32 cannot hold a single file bigger than 4 GB. This is the classic exam line. NTFS and exFAT do not have this limit.

Example

A 5 GB video will not copy to a FAT32 pen drive. Why?

Show solution

5 GB is more than 4 GB.
FAT32 has a 4 GB single-file limit.

Answer

FAT32 limits a file to 4 GB. Use NTFS or exFAT.

⚡ Wildcards

The question mark masks exactly one character. The asterisk masks any number. So *.docx finds all Word files.

Example

Which wildcard stands for any number of characters?

Show solution

? is exactly one character.
The other symbol is the asterisk.

Answer

The asterisk (*)

Mistakes to avoid

Where most students lose marks on this subtopic.

Mistake 01

Thinking FAT32 can store a 6 GB movie.

FAT32 stops at 4 GB per file. Use exFAT or NTFS.

Mistake 02

Using ? to match many characters.

? matches exactly one character. Use * for any number.

Mistake 03

Thinking a format makes the disk bigger or repairs files.

Formatting lays down a file system. It does not add space.

Mistake 04

Using \ or : in a file name.

Windows rejects \ / : * ? " < > | in names.

Mistake 05

Thinking move leaves a copy behind.

Copy leaves the original. Move removes it from the old place.

Quick revision

Read this the night before the exam.

FAT32 = pen drives, 4 GB single-file limit. exFAT removes the limit.
NTFS = Windows default, with permissions, journaling and encryption.
FAT = File Allocation Table. NTFS = New Technology File System.
Formatting lays down the file system. Cleanup deletes junk. Defragmenting joins file pieces.
? = exactly one character. * = any number of characters.
Forbidden name characters: \ / : * ? " < > |
.exe = program, .zip = archive, .docx/.xlsx/.pptx = Word, Excel, PowerPoint.

Practice: 15 questions

Sets of 10, mixed across the question types above. Every answer has a step-by-step explanation.

Topic test · 10 questions

Suggested time 4 min · wrong answers go to your mistake notebook automatically.

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