This document provides an introduction and overview of online learning. It defines online learning as learning assisted by the internet and other online facilities that allows learning to span time and distance. The document discusses the history and evolution of e-learning from the 19th century to today. It outlines some common tools used in online learning like email, chats, forums, and video conferences. It also covers elements, benefits, drawbacks, blended learning, and learning management systems related to online learning.