The filename suggests a "split archive" or "multi-volume" feature, which is a highly useful tool in file compression. How it works
To access the original content, you generally need (part1, part2, etc.) in the same folder. When you open the first part with a tool like WinRAR or 7-Zip , the software automatically "stitches" them back together into the original single file. KE4.part5.rar
It allows you to bypass file size limits on email (often 25MB) or messaging apps by sending each part individually. The filename suggests a "split archive" or "multi-volume"