Implied odds refer to what you could project that you will win if you hit your hand.
Lets say that you have 66. You have $100 and a guy who also has $100 raises to $5.
You can figure that he has a high pair or maybe AK. You call with your 66 because although you may be behind now, you know if you hit a set of 6's youre going to win a big pot.
If the flop comes A62 and he has AK, youre going to win a big pot, maybe take his whole stack if he cant let go of his top pair top kicker
Or if the flop is J62 and he has AA or KK, you are libel to take his entire $100
So although your actual odds of hitting a set are 7.5-1, your implied odds can be as high as 20-1 if you get his whole stack, so its correct to call.
Another example: You have
[7s]. The flop comes
[9s][6d].
The pot is $4. Someone bets $4. Someone else calls $4. There is now $12 in the pot. You are getting 3-1 to call $4 which is lower than the actual odds of hitting a straight on the next card, but the call is correct to make because you have large implied odds (if the opponents have enough money) if you hit your straight.
If a ten or 5 hits the turn, you will win a big pot because you will have the nuts and it will be pretty well disguised. So you can project how much you might win based on how much money the other players have in front of them. That is implied odds.