The purpose of TRB is to align incentives between users, data reporters, and the community of token holders. It accomplishes this through the following:
Tellor Tribute (TRB) tokens are used to fund contracts that provide payment to data reporters. This eliminates the need for off-chain payment agreements.
Data submissions to the Tellor database are validated via economically rational community consensus.
Tellor Reporters are required to deposit (stake) a TRB bond as collateral against “bad” or malicious data. If a questionable value is reported, any TRB holder can deposit some of their own tokens (the “dispute fee”) to initiate a dispute on that value.
TRB holders then vote on the dispute. If the dispute is supported, the disputer takes the reporter’s stake. If the dispute is challenged by the community, the reporter receives the dispute fee.
A more detailed breakdown of Tellor security can be found here.