There are two fundamentally different types of torrent: a single-file torrent and a package torrent. A single-file torrent contains only one (often very large) file to be distributed through the BitTorrent system.
A package torrent on the other hand containes several files which are downloaded as a unit. This is very similar in concept to a ZIP, RAR or TAR file.
If multiple files need to be distributed, creating a package torrent is one option. However unlike other packaging tools such as ZIP files, package torrents do not take advantage of compression to reduce the download size. Thus in most cases it is preferrable to ZIP or RAR multiple files together into a single file, and create a simple single-file torrent.