7zip is great if you are zipping up your own data. RAR is used on the internet because large files get broken up into smaller parts to get transferred and you

7zip is great if you are zipping up your own data. RAR is used on the internet because large files get broken up into smaller parts to get transferred and you can use RAR to determine whether your compressed fileset is legitimate or if it needs repair. That's where recovery volumes come in. If it won't unrar, then you can just add enough recovery files until it does.