Passphrases differ from passwords only in length. Pass words are usually short -- six to ten characters. Short passwords are OK for logging onto computer system that are programmed to detect a large number of incorrect guesses and protect the stored passwords properly, but they are not safe for use with encryption systems.
Passphrases are usually much longer -- typically 20 to 40 characters, sometimes more. Their greater length makes passphrases more secure.
The example that can be downloaded from these pages contains word lists in a couple of western languages and a generator that can create a phrase.