Smaller Files
Compression packs data into fewer bytes. Some methods shrink files without changing what you notice; others trade quality for size.
- Explain compression as finding patterns to store shorter
- Contrast lossless and lossy compression in plain words
- Choose sensible formats for school projects
Finish first
Topic contents
Lesson 1 of 3
Why files feel huge
A short video can be hundreds of megabytes because it stores millions of pixels many times per second plus sound samples too. Raw data adds up fast.
Compression looks for repetition and shortcuts. Instead of writing red fifty times, a file might say red times fifty.
Watch the step-flow animation. See repeated pixel rows replaced with a shorthand code.
Lesson 2 of 3
Lossless and lossy
Lossless compression, like ZIP or PNG, unpacks to exactly the original bits. Good for homework archives and sharp diagrams.
Lossy compression, like JPEG or MP3, throws away details humans rarely notice. Files shrink more, but saving again and again can add ugly artefacts.
Pick lossy for photos on a class blog where speed matters. Pick lossless for science graphs with thin lines you must read.
Lesson 3 of 3
Practical school choices
Export slides as PDF when layout must stay fixed. Use compressed JPEG for background photos that fill a slide.
When a teacher says file too large, try lower resolution or higher compression before deleting content.
You finished digital media. You can now explain pictures, screens, sound and file size with numbers, not mystery.
Practice
Work these out yourself
No answer key here on purpose: these are the questions worth thinking through before you move on. Open one and work it out.
0/3 attemptedAssessment
Check your understanding
Answer each question, then read the explanation. That is where the learning is.
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