The document discusses the topics of Web 3D, WebGL, and 3D interaction on the web. It provides definitions and history for these topics. WebGL allows 3D graphics rendering within web browsers without plugins using OpenGL ES. It works by using shader programs written in GLSL to render 3D graphics on a canvas element. The document discusses challenges with 3D interaction due to the 2D nature of displays and inputs, and covers various techniques for 3D input and output. Examples of 3D applications using these technologies are also mentioned.