In polling, a computer or controlling device waits for an external device to emit a signal confirming its state. The computer does nothing, rather than wait until the external device has confirmed its availability. This could be compared to an individual waiting to talk to another person who is busy attending others at a cocktail party.
In token-passing, the signal (or token) is passed between nodes to authorize a certain node to communicate. There is no "master node". This can be compared to a conversation between multiple in which some are simultaneously exchanging information with others. There is no moderator.
