You're packing for a trip. Lossless packing: You vacuum-seal clothes to remove air - they're smaller but unfold perfectly. Lossy packing: You leave your winter coat home and pack a thin jacket instead - much lighter, but not quite the same. Lossless compression is like vacuum-sealing - you can get the exact original back. Lossy compression is like leaving stuff behind - the result is good enough but some detail is permanently gone. Photos, music, videos = usually lossy (you won't notice). Documents, programs, medical scans = always lossless (need exact original)!
This introduction covers The Travel Packing Problem within Compression for GCSE Computer Science. Revise Compression in 3.3 Data Representation for GCSE Computer Science with 16 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 1 of 12 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Compression
Which statement correctly describes lossy compression?
Explain how run-length encoding (RLE) works to compress data.