How do you explain a wormhole?

Excuse me, could you please elaborate on the concept of a wormhole? I've heard it mentioned in the context of cosmology and physics, but I'm still a bit hazy on the details. Could you simplify it for me? Is it some sort of bridge connecting two distant regions of space? Or does it have something to do with time travel? I'm quite curious to understand how this hypothetical structure could work and what implications it might have for our understanding of the universe. Would you mind explaining it in layman's terms?