This document discusses and compares different types of smart devices including Google Glass, smart watches, and smartphones. It provides explanations of each device, diagrams, features and applications. Some key points made are that Google Glass is a wearable computer with an optical head-mounted display developed by Google, smart watches are computerized wristwatches that display information by connecting to smartphones, and smartphones have advanced computing abilities like keyboards, operating systems and software. The document also discusses advantages and disadvantages of each device as well as future applications.