1.1 Explain common operating system (OS) types and their purposes
📘CompTIA A+ Core 2 (220-1202)
A filesystem is the method an operating system uses to store, organize, name, and retrieve data on a storage device such as a hard drive, SSD, USB drive, or memory card.
Different operating systems use different filesystem types, and each filesystem has specific features, limits, and use cases.
For the CompTIA A+ exam, you must understand what each filesystem is, which OS uses it, its main features, and where it is commonly used in an IT environment.
1. New Technology File System (NTFS)
Overview
NTFS is the default filesystem for modern Windows operating systems (Windows 10, Windows 11, Windows Server).
Operating System
- Windows
Key Features
- Supports large files and large storage volumes
- Supports file and folder permissions
- Supports encryption
- Supports compression
- Supports disk quotas
- Supports journaling (tracks changes to prevent data corruption)
Why NTFS Is Important
NTFS provides security, reliability, and advanced management, which are required in professional IT environments.
Common IT Uses
- Internal hard drives and SSDs in Windows computers
- Windows system partitions
- Business and enterprise environments
- File servers running Windows Server
Exam Notes
- NTFS is more secure than FAT32 and exFAT
- NTFS supports Access Control Lists (ACLs) for permissions
- Required for many Windows features
2. Resilient File System (ReFS)
Overview
ReFS is a newer Windows filesystem designed for high data integrity and fault tolerance.
Operating System
- Windows (mainly Windows Server and advanced editions)
Key Features
- Designed to detect and repair data corruption
- Supports very large storage volumes
- Works well with Storage Spaces
- Improved reliability compared to NTFS
Limitations
- Cannot be used as a boot filesystem
- Not supported on all Windows editions
Common IT Uses
- File servers
- Data storage systems
- Virtualization environments
- Large storage arrays
Exam Notes
- ReFS focuses on data protection, not performance
- Used mainly in server environments, not typical desktops
3. File Allocation Table 32 (FAT32)
Overview
FAT32 is an older and very widely supported filesystem.
Operating System
- Windows
- macOS
- Linux
- Embedded systems
Key Features
- Very high compatibility
- Simple filesystem design
Limitations
- Maximum file size: 4 GB
- Less secure (no permissions or encryption)
- Less reliable for modern systems
Common IT Uses
- USB flash drives
- Memory cards
- Devices that must work with many operating systems
Exam Notes
- FAT32 is chosen for compatibility, not security
- The 4 GB file size limit is a very important exam point
4. Fourth Extended Filesystem (ext4)
Overview
ext4 is the default filesystem for most Linux distributions.
Operating System
- Linux
Key Features
- Supports large files and large partitions
- Uses journaling to prevent data corruption
- Fast and stable
- Backward compatible with ext2 and ext3
Common IT Uses
- Linux desktops
- Linux servers
- Cloud and virtualization systems
Exam Notes
- ext4 is the most common Linux filesystem
- Reliable and widely supported in Linux environments
5. Extended Filesystem (XFS)
Overview
XFS is a high-performance filesystem designed for large files and large storage systems.
Operating System
- Linux
Key Features
- Very fast with large files
- Supports large volumes
- Uses journaling
- Efficient for enterprise workloads
Common IT Uses
- Enterprise Linux servers
- Media storage systems
- High-performance computing environments
Exam Notes
- XFS is optimized for performance and scalability
- Often used when handling very large files
6. Apple File System (APFS)
Overview
APFS is the default filesystem for modern Apple devices.
Operating System
- macOS
- iOS
- iPadOS
- tvOS
- watchOS
Key Features
- Designed for SSD and flash storage
- Supports encryption
- Supports snapshots
- Fast file operations
- Space sharing between volumes
Common IT Uses
- Mac computers
- Apple mobile devices
- Apple-based enterprise environments
Exam Notes
- APFS replaced HFS+
- Optimized for speed, security, and reliability
7. Extensible File Allocation Table (exFAT)
Overview
exFAT is a modern replacement for FAT32, designed to support large files while remaining compatible.
Operating System
- Windows
- macOS
- Linux
- Many consumer devices
Key Features
- Supports very large files
- More modern than FAT32
- Good cross-platform compatibility
Limitations
- Less secure than NTFS
- No advanced permissions
Common IT Uses
- USB flash drives
- External hard drives
- Devices shared between Windows and macOS systems
Exam Notes
- exFAT does not have the 4 GB file size limit
- Used when cross-platform compatibility is required
Quick Exam Comparison Summary
| Filesystem | Primary OS | Best Use |
|---|---|---|
| NTFS | Windows | Secure Windows systems |
| ReFS | Windows Server | Data integrity and storage |
| FAT32 | Multiple OSs | Maximum compatibility |
| ext4 | Linux | Default Linux filesystem |
| XFS | Linux | High-performance storage |
| APFS | Apple OSs | Modern Apple devices |
| exFAT | Multiple OSs | Large files, portable storage |
Key Points to Remember for the Exam
- NTFS = Windows + security + permissions
- ReFS = Windows Server + data protection
- FAT32 = compatibility + 4 GB file limit
- ext4 = default Linux filesystem
- XFS = performance and large files
- APFS = Apple devices + encryption
- exFAT = cross-platform + large files
