Memory & StorageComparison

Lossless vs Lossy Compression

Part of CompressionGCSE Computer Science

This comparison covers Lossless vs Lossy Compression within Compression for GCSE Computer Science. Revise Compression in Memory & Storage for GCSE Computer Science with 15 exam-style questions and 16 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 8 of 11 in this topic. Use this comparison to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 8 of 11

Practice

15 questions

Recall

16 flashcards

Lossless vs Lossy Compression

Aspect Lossless Lossy
Data Loss None - perfect reconstruction Permanent - some data removed
Compression Ratio 30-70% smaller (moderate) 80-95% smaller (extreme)
Reversible Yes - decompress to exact original No - cannot recover lost data
Best For Text, programs, medical images, legal docs Photos, music, video, web images
Examples PNG, ZIP, FLAC, GIF JPEG, MP3, MP4, AAC
When to Use When every bit matters / exact copy needed When human perception is primary concern

Keep building this topic

Read this section alongside the surrounding pages in Compression. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Compression

Which statement correctly describes lossy compression?

  • A. The original file can be perfectly restored after decompression.
  • B. Data is permanently removed and the original cannot be exactly recreated.
  • C. The compressed file is always the same size as the original.
  • D. No data is removed during the compression process.
1 markfoundation

Explain how run-length encoding (RLE) works to compress data.

3 marksstandard

Quick Recall Flashcards

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