For 12 year old Katherine the computer is her maths teacher! That in essence means that Katherine is being taught math lessons by an online tutor. Simply speaking it is just another new age techno version of one to one teaching. A person who is qualified enough on a particular subject takes the task to teach a student who is physically separated from the teacher. This separation may be of a city, state, country or even continent. The whole point is that it's done via internet, through specifically designed softwares, chat rooms, and websites. All that it needs is the student and the teacher with computers enabled with internet.