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J277 1.5.2 Utility software

Part 2 of 3 · J277 1.5 · Systems software

Utility software as system housekeeping, with focused practice on encryption, defragmentation and compression.

Students will:

  • state the general purpose of utility software
  • explain encryption and its limits
  • explain how defragmentation rearranges file parts on a magnetic HDD
  • distinguish compression from capacity changes and encryption
  • recommend an appropriate utility for a stated need

Inside: 6 text sections, 2 multiple-choice activities, 3 completion activities, 5 written answers. 22 marks. Suggested teaching time: 45–60 minutes. 1 diagram.

Includes a teacher guide with suggested sections, timings and common misconceptions.

Series: J277 1.5 · Systems software, part 2 of 3.

Shared by Coding PathwayVerified teacher

  • 16 cells
  • About 60 minutes
  • CC BY-SA 4.0
  • Shared 17 Aug 2026
  • Updated 27 Oct 2026

Preview

The whole resource, exactly as a class sees it. Answers and marking are held back.

Utility software

Utility software performs focused housekeeping tasks: maintaining, monitoring, managing or protecting a computer system. It adds tasks that the OS may not carry out itself. Utilities can be bundled with an OS or installed separately.

The three utilities in this topic are encryption, defragmentation and data compression. Their jobs are different.

Written answer1 mark

State the general purpose of utility software.

Students type their answer here.

1. Three jobs

UtilityMain job
EncryptionTransforms data so it cannot normally be understood without the appropriate key.
DefragmentationRearranges separated parts of files on a magnetic HDD.
Data compressionRepresents file data using fewer bits.

Each utility acts on data or its organisation. Installing utilities does not increase a drive's physical capacity.

Fill in the blanks3 marks
Answer 1 protects the meaning of copied data. Answer 2 rearranges separated file parts. Answer 3 reduces the bits needed for a file.
  • encryption
  • defragmentation
  • data compression
  • file management

2. Protect meaning, not physical access

Encryption uses an algorithm and a key to transform readable plaintext into ciphertext. An appropriate key allows the recipient to decrypt the data.

Someone may still steal a drive or copy its files. The protection is that the copied ciphertext should be meaningless without the key. Encryption does not stop interception, copying or deletion.

Written answer3 marks

A researcher stores private survey notes on a laptop. Explain how encryption protects the notes if someone copies the files without permission.

Students type their answer here.

Multiple choice1 mark

A thief obtains an encrypted file but has no suitable key. What protection does encryption provide?

  • AIt guarantees the thief cannot delete the copy
  • BIt stops the thief obtaining any copy
  • CIt makes the file's meaning difficult to recover without the key
  • DIt increases the laptop's storage capacity

3. Bring a file's parts together

As files are added and deleted on a magnetic hard disk drive (HDD), new files may be split between available spaces. Their separated parts are called fragments.

Defragmentation finds these parts and moves parts of the same file into consecutive locations. Free areas can also be brought together. The read/write head travels less between file parts, so access can be quicker.

Defragmentation rearranges parts of the same file Six disk locations before and after defragmentation. Before, A1, A2 and A3 are separated by free locations and file B. Afterwards, all three parts of A are consecutive, followed by B and two free locations. No file data has been removed and the number of locations stays the same. Parts of file A on a magnetic HDD Before AfterA1freeBA2freeA3A1A2A3Bfreefree Same file data; parts now together. The drive's capacity is unchanged.

An SSD has no moving read/write head. This mechanical access-time reason does not apply to an SSD, and this kind of defragmentation is not needed for it.

Fill in the blanks3 marks
Defragmentation moves parts of the Answer 1 file into Answer 2 locations. On a magnetic HDD, this reduces movement of the read/write Answer 3.
  • same
  • similar
  • consecutive
  • head
  • capacity
Written answer3 marks

Explain how defragmentation can make reading a fragmented file from a magnetic HDD quicker.

Students type their answer here.

Multiple choice1 mark

Why does the moving-head explanation for defragmentation not apply to an SSD?

  • AAn SSD stores no files
  • BAn SSD has no mechanical read/write head to move between locations
  • CAn SSD has unlimited storage space
  • DAn SSD automatically encrypts every file

4. Use fewer bits

Data compression reduces the number of bits needed to represent a file. The file needs less storage space and less data must be transferred. Transfer can take less time when the connection speed stays the same.

Lossless compression allows exact reconstruction of the original data. Lossy compression permanently removes some data and may reduce quality; it can be suitable when that change is acceptable. Compression reduces file size, not the capacity of the drive or the bandwidth of a network.

Written answer2 marks

A club needs to upload a large video. Explain how compressing the video could reduce upload time if the connection speed stays the same.

Students type their answer here.

Written answer2 marks

A program must work exactly as before after it is compressed and decompressed. Explain why lossless compression is suitable.

Students type their answer here.

Fill in the blanks3 marks
Name the suitable utility. (a) Protect the meaning of confidential files copied from a portable drive: Answer 1 (b) Reorganise scattered parts of files on a magnetic HDD: Answer 2 (c) Reduce a file's storage requirement: Answer 3

Review

Improve one answer by adding the missing link between what the utility changes and the benefit that follows.