For a number of good reasons, many files that you find on the Internet are compressed. Before you can use these files, they have to be decompressed. You can usually recognize compressed files by their suffixes, most commonly the suffix .zip. If you know anyone who downloads very many files from the Internet, that person can almost surely help you with decompressing files. You may find that you have a program for decompressing files on your computer already. Current operating systems usually display compressed files as directories or folders. To decompress a folder, right-click on it, and choose the option you want. Usually “Extract All” is the option that works best.
Usually, interpreters for interactive fiction are compressed when you find them on the Internet. Interactive fiction story files are usually not compressed.