Zipped (compressed) files take up less storage space and can be transferred to other computers more quickly than uncompressed files.
How to zip a file or folder on Windows
Locate the file or folder that you want to zip.
Press and hold (or right-click) the file or folder, select (or point to) Send to, and then select Compressed (zipped) folder.
3. A new zipped folder with the same name is created in the same location. To rename it, press and hold (or right-click) the folder, select Rename, and then type the new name.
How to zip a file or folder on Mac
Click the Finder icon in your Mac's Dock to make sure it's the active application.
Right-click (or Control-click) on the file or folder you want to compress. Alternately, drag a selection box over several files and/or folders with your cursor by holding down the left mouse button or pressing down on the trackpad.
Select Compress [name of file] or Compress X Items from the contextual dropdown menu.
4. Locate the newly created zip file in the same directory as the original files and/or folders.
If you compressed a single file, the zip archive takes the same name and adds a zip extension. If you compressed more than one file or folder, the zip archive will be named "Archive.zip" by default.