Is online and multiplayer online the same

Online is that you can internet, that people could connect to you, and you can connect to people. But not only people, also hosts (like games & websites)

Multiplayer is that you're playing with someone, you can do multiplayer offline, then he have to play on the same game concole you're playing on. And online multiplayer is that you're online (on the world wide web) that you can do multiplayer with someone in another place of the world. As long you're both online.