WebGL (Web Graphics Library) is a JavaScript API for rendering interactive 3D and 2D graphics within any compatible web browser without the use of plug-ins. WebGL does so by introducing an API that closely conforms to OpenGL ES 2.0 that can be used in HTML5 elements.

WebGL programs consist of control code written in JavaScript and special effects code (shader code) that is executed on a computer's Graphics Processing Unit (GPU). WebGL elements can be mixed with other HTML elements and composited with other parts of the page or page background.

WebGL is pretty well supported by most browsers. Support for WebGL is present in Firefox 4+, Google Chrome 9+, Opera 12+, Safari 5.1+, Internet Explorer 11+, and Microsoft Edge build 10240+; however, the user's device must also have hardware that supports these features.

A Geometry is the mathematical formula of an object, in Three.js we have many geometries, we’ll explore it in future chapters. A Geometry gives us the vertices of the object we want to add to the scene.

A Material can be defined as the properties of an object and its behavior with the light sources of the scene. As you can see in the following image there are different types of materials.

• MDN WebGL: 2D and 3D graphics for the web
• MDN WebGL tutorial
• Three.js 101 : Hello World! (Part 1)