Lossy vs lossless compression (1.3.1 a)

Question 1

Compression

Answer 1

without some level of compression files get unusably large very quickly
compression reduces the file size while keeping the file usable

Question 2

Lossless compression

Answer 2

always reversible
a file that uses it can be decompressed without losing any data
original data can be restored

Question 3

Lossy compression

Answer 3

irreversible
data is permanently deleted in the process
file cannot be restored to its original state
can reduce file size much more than lossless
used for viewing/distributing multimedia e.g video audio
not appropriate for text or when you need all the data eg when editing the files
how much data is removed can be adjusted
e.g JPG WebP H.264 MP3 MP4