Utility software

OCR J277 Paper 1 sets short-answer questions on utility software. Utility software performs maintenance tasks that keep the computer running well. Each utility has a clear, narrow purpose — make sure you can state what it does and why the user runs it.

Encryption software

Encrypts files, folders or whole drives using a key. Plain text becomes cipher text — unreadable without the key.

• Protects data at rest (theft of laptop or disk) and in transit (VPN, HTTPS).
• Examples — BitLocker, FileVault, VeraCrypt.
• Trade-off — encrypting/decrypting takes CPU time; lose the key and the data is unrecoverable.

Defragmentation software

Used on mechanical hard disk drives (HDDs). Over time, files are split into fragments scattered across the platter. The read/write head must move (seek) to each fragment, slowing access.

• Defragmentation rearranges files so each is stored in contiguous sectors, plus contiguous free space.
• After defragging, fewer head seeks → faster reads.
• Should NOT be run on SSDs — SSDs have no seek penalty, and defragging causes unnecessary writes that wear out the cells.

Data-compression software

Reduces file size by removing redundancy.

• Lossless — original data fully recovered. Examples: ZIP, FLAC, PNG.
• Lossy — discards information judged unimportant; smaller files but data permanently lost. Examples: JPEG, MP3.
• Benefits — saves storage, faster transmission, smaller backups. Cost — CPU time to compress and decompress.

Back-up software

Copies files to a secondary location so they can be restored if the original is lost (hardware failure, ransomware, accidental deletion).

• Full backup — copies everything; slow but easy to restore from.
• Incremental backup — copies only what has changed since the last backup of any kind; fast to make, slower to restore (need full + every incremental).
• Differential backup — copies what has changed since the last full backup; medium speed, easier to restore (full + most recent differential).
• Best practice — keep at least one off-site copy (cloud or removable disk stored elsewhere) and test restores regularly.

Common OCR exam mistakes

• Defragging an SSD — wastes write cycles and gives no speed benefit.
• Saying compression "deletes files you do not need" — compression keeps the file but encodes it more efficiently. Lossy compression discards detail within the file, not whole files.
• Confusing backup with copying — backup software is automated and scheduled, manages versions, and stores in a separate location.
• Saying encryption stops viruses — it protects confidentiality, not integrity against malware.