Pot odds is what we're calling now to win now.

Implied odds comes in to play when there are people to act behind you or on later streets.

Let's say you're 2nd to act in a 4way pot and you have the NFD. PF, the pot is 16BB and 1st to act opens the flop for 12BB. You have to call 12 to win 28, giving you pot odds of 2:1 against drawing 4:1. Heads up, you can't profitably call here.

But let's say the two to act behind are known to call down light, and you're pretty sure they will call. Theoretically, you can use their expect call to calculate odds. In this case, you're calling 12BB into not 28, but into 52, giving you pot odds of just under 6:1. You can call profitably.

Implied odds are the reason why speculative hands work better multiway. You don't win too often, but it's a large pot when you do.