“I have a series of compressed files... some are .7z.001. From my understanding, this normally means it's part of a split archive.” Reddit · r/techsupport · 6 years ago
: It was created using 7-Zip , a free tool known for high compression ratios and strong encryption. How to use it
“7zip file with numbers on it like 001 means that you only have a part file of the whole compressed file.” Microsoft Learn