The reason you (don't) need blend1 files

pavla writes:

What's that filling up your hard drive? Yep, it's them: blend1 files.

What is a blend1 file and how do they work?

Let’s say you’re working on a file called “Cool_project.blend”

Normally, every time you save, this file is directly overwritten. However, if you have blend1 files enabled before it is overwritten, the old filename extension is renamed to blend1. And if blend1 already existed, it becomes blend2, and blend2 becomes blend3, etc..all the way up to however many copies you told Blender to keep (the limit is 32 saved versions).