Subsumption architecture is a method for programming robots to do lots of complex tasks. It is made up of several layers of robot "behaviors" that work together to help the robot know what to do in any given situation. Each behavior is like a set of instructions that tell the robot what to do when certain conditions are met. For example, if the robot's sensors detect something in its path, one behavior might be to avoid it, while another behavior might be to follow it. All the behaviors are put together and they become like a big map that the robot can use to figure out what to do in different situations.