An exercise book is a notebook used by students to write down their work while learning or practicing a particular subject or skill. It is typically used to record notes, examples, and exercises completed during a lesson or as homework. The purpose of an exercise book is to provide a record of a student's progress and to provide a reference for reviewing and reinforcing the material learned. Exercise books can also be used as a tool for self-study and self-assessment, allowing students to track their own progress and identify areas where they need to focus more attention.