Everything is stored as files in a computer system. The files can be data files or application files. Each operating system has its own way of organizing data internally. The operating system performs this management with the help of a program called File System. The type of file system is used to determine how data and programs are accessed. It also determines the level of accessibility available to users.

The following are the different types of file systems.

FAT File System

FAT stands for “File Allocation Table”. The file allocation table is used by the operating system to locate files on a disk. A file may be divided into many sections and scattered around the disk due to fragmentation. FAT keeps track of all pieces of a file. In DOS systems, FAT is stored after boot sector. The file system has been used since the advent of PC.

Features of FAT File System

Some important features of  the FAT File System are as follows.

Naming convention

  • FAT file system used by MS-DOS provides file name of only 8 characters long.
  • FAT file system used by Windows 2000 supports long file name. The full path of file including filename can be up to 255 characters long.
  • File names can contain any character except “/ [] = , ^ ?a “”
  • File names should begin with alphanumeric characters.
  • File names can contain spaces and multiple periods. The characters after the last period are treated as file extension.


FAT does not support local and folder security. A user logged on a computer locally has full access to the files and folders in FAT partitions of the computer.

Quick Access to files

FAT provides quick access to files. The speed of file access depends on file type, file size, partition size, fragmentation and number of files in a folder.

FAT32 File System

FAT32 is an advanced version of FAT file system. It can be used on drives from 512 MB to 2TB in size. One of the most important features of FAT and FAT32 is that they offer compatibility with operating systems other than Windows 2000 also.

Features of FAT32 File System

FAT32 has the following features.

Partition size

FAT32 increases the number of bits used to address cluster. A cluster is a set of sectors. It reduces the size of each cluster. It supports larger disk (up to 2TB) and better storage efficiency.

Access Speed

FAT32 provides good file access in partition sizes less than 500 MB or greater than 2 GB. It provides better disk space utilization.

NTFS File System

NTFS stands for “New Technology File System”.Windows 2000 professional fully supports NTFS. It has the following characteristics.

Features of NTFS File System

The following are some of the main features of NTFS File System.

Naming Conventions

  • File names can be up to 255 characters
  • File names can contain most characters except “ / < > * | :
  • File names are not case sensitive


NTFS provides file and folder security. Files and folders are safer than FAT. Security is maintained by assigning NTFS permissions to files and folders. Security is maintained at the local level and the network level. The permissions can be assigned to individual files and folders. Each file or folder in an NTFS partition has an Access Control List. It contains the users and group security identifier (SID) and the privileges granted to them.

Partition Size

The NTFS partition and file sizes are much bigger than FAT partitions and files. The maximum size of an NTFS partition or file can be 16 Exabyte. However, the practical limitation is two Terabytes. The file size can be in the range of 4GB to 64GB.

File compression

NTFS provides file compression of as much as 50%.

High reliability

NTFS is highly reliable. It is recoverable file system. It uses transaction logs to update the file and folders logs automatically. The system also has a great amount of fault tolerance. It means that if transaction fails due to power or system failure, the logged transactions are used to recover the data.

Bad cluster Mapping

NTFS supports bad-cluster mapping. It means that file system detects bad clusters or areas of disk with errors. If there is any data in those clusters, it is retrieved and stored on another area. The bad clusters are marked to prevent data storage in those areas in futre.

Read our article about the difference between FAT and NTFS file system