Three key types of utility software are encryption software (protecting data), defragmentation software (reorganising fragmented files), and data compression software (reducing file sizes).
Key points
Definition:Encryption Software: uses complex algorithms to encrypt data, making it unreadable without the correct decryption key. Can encrypt specific files or an entire hard disk.
Definition:Defragmentation Software: reorganises files on a hard disk drive so that file fragments are stored together in contiguous blocks, improving access speed.
Definition:Data Compression Software: reduces file sizes so they take up less storage space and can be transmitted more quickly.
Defragmentation is ONLY useful for HDDs (magnetic drives with moving read/write heads). SSDs do NOT need defragmentation because they can access any location equally fast.
Exam Tip:Defragmentation improves HDD performance by reducing the distance the read/write head needs to travel. It is NOT needed for SSDs.
Common Mistake:Saying defragmentation works on SSDs. SSDs have no moving parts, so fragmentation does not affect their performance.
Fragmentation occurs over time as files are created, modified, and deleted — pieces of files become scattered across the disk.
Exam Tip:Encryption software uses a KEY (not a 'lock') to scramble data. If the data is intercepted, it cannot be UNDERSTOOD. Note: encryption does not STOP interception.
Exam Example:'Explain how fragmentation occurs in a restaurant ordering system' — orders are saved then deleted; new orders may be bigger than the deleted spaces; files get split up and stored in non-contiguous locations.
Exam Tip:Defragmentation moves files to be CONSECUTIVE/CONTIGUOUS in storage and collects free space together. The read head does not need to move as far → faster access. It does NOT create more storage space.
Exam Tip:After defrag, SAVING new files is also faster because free space is grouped together, so new files can be stored without splitting.