Compression, encryption, hashing

to use as flashcards

How does lossless compression work?

File is shrunk, but the effects are reversible

How does lossy compression work?

File is shrunk and pieces of data are permanently lost

What is run length encoding?

A lossless compression method where repeating data/sequences are stored as one value and a count indicating how many times it repeats in a row. e.g. 3R,4G,2B

In images, similarly coloured pixels are often assigned the same value.

What is dictionary coding?

A lossless compression method where every unique word is added to a dictionary where a binary number is assigned to it.