Archive mastery with a classic workhorse WinRAR is a powerful file compressor and decompressor. It has been around for many years, How to Open RAR Files on Windows, Mac, and Mobile - Avast

A RAR file is a proprietary archive format that "shrinks" files to save space.

Always be careful when downloading small archives from unknown sites. Even a 449K file can contain scripts or malware that only "activate" once you extract them.