Communication is the exchange of information between individuals or gropus. It is used in everyday life, whether to learn something, obtain education or talk with somebody else.
Proactive communication is a particular kind of communication where a person solves problems, clarifies doubts, or deals with claims in advance. A proactive communicator does not wait for the other people to inform their worries, he/she acts in anticipation to prevent them.
In school, these contrasts can make a difference. You can make use of communication with the teacher to clarify your doubts about a particular subject. In that way, you will possibly avoid having problems to understand the subject. On the other hand, the teacher will make use of proactive communication to make the educational process as effective as possible. As a result, he/she can anticipate the problems students can find in certain situations by giving them possible solutions.