5.2: Utility Software
What is utility software?
Utility software are dedicated programs used for the maintenance and organisation of a computer system.
Anti-malware (such as an anti-virus or anti-spyware), firewall and encryption software are examples of utilities and have been explained in section 4.2.
Data Compression is another utility that has been explained in section 2.5.
Other utility software include backup software, disk checkers, disk formatters and auto-updaters.
What is fragmentation and how does it happen?
Over time files stored on a hard disk drive may become fragmented - this is when the file is split into parts that are saved in different storage locations.
Fragmentation occurs when there is limited contiguous space in which to store a file. This may happen as data is stored and then later deleted on the hard drive. New files are created which may be bigger than the spaces left by the deleted files. The new files are then split up.
Fragmentation increases access time - files that are fragmented take longer to load and read because of the distance between the fragments of the file.
How does defragmentation work?
Empty spaces are collected together on the hard disk drive and file fragments are moved to be stored together.
This means that fewer disc accesses are needed (requiring less physical movement) as file fragments can be read consecutively.
What are the effects of defragmentation?
A defragmented file takes less time to read and access because the data is stored contiguously. The read/write head of the hard drive does not need to move as far to read the next piece of data because it is in the adjacent memory location, saving time.
It also quicker to save new files because there is more free space together so it does not need to split the file and can store the data contiguously.
5.2 - Utility Software:
1. Explain what fragmentation is and how a file may become fragmented. 
2. Describe the process of defragmentation. 
3. Explain the effects of defragmenting a hard disk drive.