They have overlapping meanings. So they can be used interchangeably in many contexts without any difference. But consciousness has multiple meanings - aside from the meaning of generally 'knowing' (which matches awareness), consciousness also has very specific meanings in medical and psychological fields. In the medical field, if you have consciousness, it means you're not dead or sleeping. In psychology, your consciousness is your localised, reflective mind, capable of advanced thought (the part of your brain which only functions when you're medically conscious), as opposed to the subconsciousness which is intuitive and non reflective (the only part of your brain which functions when you're sleeping).

I'd like to add - depending on how philosophical you get, "consciousness" is very hard to define. It's the sort of word where you'll get different definitions depending on who you ask. Actually, Dan's response exemplifies this. In contrast, "awareness" is more straightforward. Generally, to say that somebody is "aware of something" is to say that that person knows that the mentioned thing exists, is true, etc. For example, if I say "He was not aware of the elephant in the room", it's another way of phrasing that "he did not know that the elephant was in the room".

Consciousness is being awake and seeing/sensing your surroundings but it can also be used kind of like awareness as well