Don't know how to compress a file

1. Locate the file or folder you want to compress (zip).
2. Right-click the file or folder, select Send to, and then select Compressed (zipped) folder.

A new zipped folder with the same name will be created in the same location. If you want to rename it, press and hold the zipped file, select Rename, and type the new name.

Feel free to watch this tutorial should the above-mentioned steps be unclear to you:

Note: To add files or folders to an already zipped file you created earlier, drag them to the zipped file.

1. Locate the items to zip (using Mac Finder);
2. Right-click on the file(s) and/or folder you want to compress (zip);
3. Select Compress x items (e.g. if you want to compress 3 items you should click on Compress 3 items);

Feel free to watch the video below should any of the above-mentioned instructions be unclear to you:

iZip is an easy-to-use app which enables you to manage ZIP, ZIPX, RAR, TAR, 7ZIP and other compressed files on your Mac. It's completely free and lets you zip, unzip & unrar your files without limitations!.

You can download it from iZip's website.