书面语 -> words you write down, like words in articles, magazines, etc.
口语 -> words you say, like words you use when chatting with your friends.
Just think about English. English also has written language (书面语) and Spoken language (口语). 书面语 is more accurate than 口语，because you take lots of time to write it and you also check it out several times after finishing it.
文言文 -> words ancient people write down
古语 -> words ancient people write down and say
旧称 -> the way ancient people call a thing. The same thing can have different names in ancient and modern.
These are some simple definitions I can think of. Hope it can help you.