Most latest versions and source code are hosted on SourceForge .
If you have Info-ZIP installed (often just called zip and unzip on your system), here are the most common ways to use it: info.zip
You can choose levels from 0 (no compression, just storage) to 9 (maximum compression). Most latest versions and source code are hosted
Here is a helpful overview post you can use to explain what it is and how to use it. info.zip
If you're looking for a or trying to fix an error (like a "zip bomb" or "corrupted file")