Class work and Home work is important as it helps a student as he/she practices that thing. Suppose you are in a maths class, then in class work the teacher will make you understand the questions and will make you write in your notebooks and in homework, questions of similar type are given to you as this will help in enriching your mental skills and will help you in understanding those questions by yourself. As sometimes many students just copy down the classwork instead of understanding it but homework makes you think about it so that you'll be able to solve it....... Same is with other subjects too. You need classwork for understanding and homework for analysing whether you got it or not.