Is kelp real?

Excuse me, but could you clarify something for me? I've been hearing some interesting conversations about kelp lately, and I'm a bit confused. Is kelp actually a real thing, or is it just some sort of myth or metaphor? I've seen it mentioned in relation to seaweed and the ocean, but I'm not entirely sure if it's a specific type of plant or just a general term. Could you help me understand if kelp is indeed a real, tangible substance that exists in nature?