Compress files or folders on a PC
ON a Windows 10 PC, compressing (and decompressing) files and/or folders is easy enough. Microsoft offers simple instructions here: https://support.microsoft.com/en-us/help/14200/windows-compress-uncompress-zip-files
There are programs that offer advanced ways and a variety of compression formats. We have been using one called 7zip for years and have found it to be quick, simple to use and efficient.
Compress files or folders on a Mac
Creating a compressed zip files is easy enough to do on a Mac OS system. Apple offers an easy to follo tutorial here: https://support.apple.com/guide/mac-help/compress-uncompress-files-folders-mac-mchlp2528/mac