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GCSE Computer Science/Paper 1/Compression

The need for compression

1.2.5 Compression

Practise exam questions

Compression — Note 1 of 2

What you need to know

Data compression reduces the file size of digital data. This is important for saving storage space, speeding up file transfers, and reducing bandwidth usage during transmission over networks.

What to know

  • Compressed files take up less storage space on devices.
  • Compressed files are faster to transmit over a network (less data to send).
  • Compression reduces bandwidth usage, which is important for streaming and downloading.

Key terms

Exam tipCommon mistake

Compression

The process of reducing the size of a file to save storage space or speed up transmission.

  • Exam tip: When asked WHY compression is needed, give at least TWO reasons: saves storage space AND speeds up transmission/reduces bandwidth.

Exam technique

  • Tip:Be PRECISE. Don't just say 'it is faster' — state WHAT is faster (e.g. 'faster to upload/download/transmit'). Don't say 'takes up less space' — say 'takes up less STORAGE space'.

Ready to test yourself?

Practise 1.2.5 questions
← Previous topicThe effect of sample rate, duration and bit depth on: playback quality, size of the sound file1.2.4d Data Storage: SoundNext note →Lossy, Lossless1.2.5 Compression

Back to Compression

Revise another OCR GCSE topic: Data Storage: Images

Compression

Note 1 of 2

  1. 1The need for compression
  2. 2Lossy, Lossless
Topic overview

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