What is a ZIP file?
ZIP files compressed files that make it faster and easier to download large files. Your purchases will be supplied as a ZIP file containing one or more folders. Once you download your file from your account in the shop (remember where on your computer you downloaded it!) you will need to unzip the contents of the ZIP before you can use them. If you are using the more recent versions of Windows, you can simply right-click on the ZIP file and select ‘Extract All’ to unzip everything. On a Mac, double click the zipped file to extract. Programs such as WinZip are a good option if your operating system doesn’t have a built-in unzip utility.
This is a useful article all about zip files: What is a ZIP file? (Teachers Pay Teachers)