Both these words can be used as conjunctions. They mean the same. Though is informal.
(Al)though I don't agree with him, I think he's honest. She went on walking, (al)though she was terribly tired. I'll talk to him, (although I don't think it'll do any good.
We use even though to emphasize a contrast. (Even although is not possible.)
Even though I didn't understand the words, I knew what he wanted.
We can use though to mean 'however'. It usually comes at the end of a sentence in informal speech.