Is Polkadot tied to Ethereum?

Could you clarify the relationship between Polkadot and Ethereum for me? I've heard some rumors that they might be interconnected, but I'm not quite sure. Could you elaborate on whether Polkadot is somehow tied to Ethereum? For instance, do they share any common functionalities or do they complement each other in some way? I'm also curious if their prices are often influenced by similar market forces. I'd appreciate your insights into this matter, as I'm trying to understand the intricate web of relationships within the cryptocurrency world.