Shrink It Down – Data Compression

​“Shrink It Down
– Data Compression”

By D Smith 18_8_25 e2010404

What is Data Compression?

Data compression makes files smaller so they use less space and send faster.

Multiple Choice

What does “data compression” mean?

• Making files bigger

• Making files smaller

• Breaking a file into pieces

• Copying a file many times

Why Do We Need It?

Smaller files download faster and take up less storage. Without compression, the internet would be much slower.

Poll

Which do you prefer?

• Watching a video instantly

• Waiting 5 minutes for it to load

Everyday Compression

Photos (JPEG), music (MP3), and videos (YouTube) all use compression.

Multiple Choice

YouTube videos are compressed before you watch them.

• True

• False

​How Does It Work?

Compression finds patterns and removes repeated data.

Text example “AAAAAA” → “6A.”

Multiple Choice

Which would compress the most?

• A text file full of “AAAAAA”

• A text file full of random letters

​Two Types of Compression

• Lossless: Nothing lost, file can return to original.

• Lossy: Some detail lost, but file is much smaller.

Multiple Choice

Lossless compression keeps all the original data.

• True

• False

​Lossy in Real Life**

MP3 music and JPEG photos use lossy compression. Quality is slightly reduced but usually not noticeable.

Poll

Would you rather…

• A slightly blurry photo that loads fast

• A perfect photo that loads slowly

​Zip Files

A ZIP file is a folder of files that has been compressed into one smaller package.

Multiple Choice

What happens when you unzip a file?

• It goes back to normal

• It disappears

• It gets smaller again

• It deletes your data

​Info & Wrap-up

Compression saves space, makes downloads faster, and helps the internet run smoothly.