The page quoted by otheus came from the book "Computer Networking - a top-down approach featuring the Internet" with Kurose as one of the authors (Addison Wesley). Consider getting yourself a copy of that one. It was the textbook for networking course in my university.

Specifically, Section 3.4 "Principles of Reliable Data Transfer" discusses the various approaches of developing reliable data transfer over an unreliable transport. That section should answer your question.