Heuristics are simple rules or mental shortcuts that allow humans to make decisions quickly and with limited information. The document discusses several types of heuristics including: the gaze heuristic, recognition heuristic, social heuristics like "do what the majority do", and heuristics based on reasons like take the best and tallying. It also covers cognitive biases like hindsight bias. Overall, the document examines how heuristics demonstrate bounded rationality and how humans use fast and frugal mental shortcuts to make decisions in an efficient manner.