ambiguous term a feature function is a function that takes in a transition so state action next state and maps it to a high dimensional vector note this is almost the same as a reward function except the reward function simply maps it to a number now this is mapped to a higher dimensional thing again i wanna i kind of wanna leave out the next state right here just to make things easier on you so a feature here can be many many things but the structure of the features is going to be such that the reward function is going to be