Award criteria are the factors a contracting authority uses to score bids and decide the winner, such as price, quality, technical merit, and delivery. They are published in the tender documents, usually with weightings.
Most contracts are awarded on the 'most economically advantageous tender' (MEAT) basis, which balances price against quality rather than picking the cheapest bid. Reading the award criteria and their weightings closely tells a bidder exactly where to focus effort to maximise their score.