As a teacher, you will probably have a TA (teaching assistant) in your class at least a few times a week. The role of a teaching assistant is to assist the teacher in whatever tasks they have to do. It is up to the teacher to give the teaching assistant duties that they would like them to be responsible for and to ensure that they are doing the job correctly.
Teaching assistants do not usually plan lessons or mark work unless they have a teaching degree but they are able to take a small group of children to work with on their own. If you have a wide range of abilities in the class then you may find it useful to split the class into smaller groups to allow you to set different work for them. The TA may be given a small group of children who maybe need a little bit more help and attention. This will allow you to teach the rest of the class as a whole.
If you have photocopying that needs doing or if you would like a display creating then you can often task this to your teaching assistant. They can also be your extra set of eyes in the classroom should you have missed a dispute or disagreement that has happened between other pupils.