Eli5: How do zip files work? How do they make files just smaller?

Question

Eli5: How do zip files work? How do they make files just smaller?

In: Technology

Answer 1

Compression is a form of coding. When you find a specific pattern or grouping, you assign that group a simple name, then replace all the reference with the simple name. For example, a long essay, you find the word “the” occurs 1200 times in the text. You add a statement that says replace the letter sequence THE with the number 1.

So for each time the word The appears, the compressed form has the number 1. You’ve now reduced the size by 66% for each occurrence of the word.

The more times a file has a repeating pattern that can be coded smaller, the better the compression ratio will be.