Visible Light Communication (VLC) is a data communications medium using visible light between 400 THz (780 nm) and 800 THz (375 nm). Visible light is not injurious to vision. Low-cost wireless communication network can be created using Visible Light Communication system. Visible Light Communication is a potential solution to the shortage of global wireless radio spectrum. Visible Light Communication can be used as a communications medium for ubiquitous computing, because light-producing devices (such as indoor/outdoor lamps, TVs, traffic signs, commercial displays, car headlights/taillights, etc.) are used everywhere. Visible Light Communication can be seen by the human eye, carry an embedded signal, which is unseen. We will set the scene by providing a general background to the subject of optical wireless communications, followed by a brief summary of the history of visible light communication VLC). We will discuss the major advantages of VLC and discuss existing challenges. Recent key advancements in physical layer techniques, such as localization, ultra-high-speed indoor connection, ultra low latency outdoor link, will be discussed at the end of the course.