Artificial life is a special branch within robotics and is closely related to behavioural robotics. It tries to mimic the behaviour of real lifeforms. I think if it as liberated robots: robots who are not a slave, (trying) to execute the commands from their masters as good as possible.
So what do these robots do? Well, they roam the world, doing the things they want to do. We humans can observe them, interact with them, try to give them commands (or should it be suggestions) and reason about their intentions and behaviour.
The robots are not perfect. In fact, when designing the robots, imperfections are intentionally left in place. These imperfections give the robots their character. Most of the time, these imperfections originate in the sensors or actuator. Examples of imperfections are not driving straight, being a bit blind or less responsive on a certain side.
Building and designing these robots give me a lot of insight on how humans, including myself, observe and respond to the world. Together with Humanoid Control, it may even result in artificial humans...