After high school many of my friends moved away to college, and we still keep in touch through email. Before I had an email account, my friends and I would communicate through snail mail and by telephone. However, it would take weeks for us to get the chance to sit down and write the letter, and then even more time to find a stamp, an envelope, not to mention the address of the recipient. Telephone calls were only made at our own free time not knowing if it was a convenient time for the other person. Long-distance phone calls also cost money.
Email is free, travels almost instantaneously, and is readable at our own convenience.
Email is also a great way for professors to send out information to students about when class will be cancelled or information that the professor has forgotten to mention in class. Email has also played a great role in mending the relationship between my father and me. My father and I have never had a good relationship, and we have always had trouble communicating with one another, especially over the phone. Once he got a computer and began using the Internet, we started emailing each other. Now we email each other about once every two weeks.