The rewards for each era consist of the transaction fees collected in the era and the emission in the era. The rewards are distributed among the Treasury and the validators. The Treasury receives 60% of the rewards and the validators get 40%. Among the validators, the rewards are distributed based on their performance in that era. The network keeps track of the contributions of each validator in the era. For each validator, the network gives rewards proportional to their performance which are then distributed to the nominators in proportion to their stake after deducting commission. For instance, if a validator is expected to receive 100 tokens in an era with a 5% commission and 3 nominators with 35%, 30%, and 20% stake each, the network would give 15 tokens (10+5) to the validator and 35, 30 and 20 tokens to each of the nominators.