Homework is an essential part of ensuring that you remember and know more about the information your teachers have taught you.
Our short-term memory is very, very limited in terms of how much and for how long it can remember things. Doing your revision homework every day will help you to take all your knowledge from your short-term memory and put it in your long-term memory.
Our long-term memory is unlimited in terms of how much and for how long it can remember things.
Details of how much homework you need to do each day, can be found here.