Compression

Question 1

2 Types of compression

Answer 1

• Lossy
• Lossless

Question 2

Summary of how lossless compression works?

Answer 2

It allows the file size to be reduced without losing any of the original data. It works by searching for patterns and indexing those patterns.

Question 3

Summary of how lossy compression works?

Answer 3

Lossy compression removed data that is not needed, either because a drop in quality is acceptable or the difference can’t be detected by the human eye.

Question 4

Why is lossy compression not good for software, databases, etc.?

Answer 4

Because in lossy compression, parts of the original data are lost meaning the data can’t be put together how it was (bad for code, databases, etc.)

Question 5

Run-length encoding.

Answer 5

It groups repetitive data and stores them once.

Question 6

Dictionary encoding

Answer 6

Dictionary encoding algorithms create an index of data which require less space to store than the original data

Question 7

3 benefits of compression

Answer 7

• Download speeds are increased
• Real-time streaming of audio and video without buffering
• Takes smaller size on disk, so you have more space to store other data