1. گرافیک رایانه ای

2. a JavaScript API for rendering interactive 3D computer graphics and 2D graphics
 without use of plug-ins
allowing GPU accelerated usage of physics and image processing
effects as part of the web page canvas

3. Canvas 3D prototype in 2006 by  Vladimir Vukićević in mozilla
2009, the non-profit technology consortium Khronos Group started the WebGL
Version 1.0 of the WebGL specification was released March 2011
In November 2012 Autodesk ported most of their applications to the cloud running on local WebGL clients. These applications included Fusion 360 and AutoCAD 360.
 WebGL 2 specification started in 2013 , based on OpenGL ES 3.0.

4. Canvas was initially introduced by Apple
use inside Mac OS X WebKit component in 2004
standardized by the Web Hypertext Application Technology Working Group (WHATWG)  in 2006

5. Canvas consists of a drawable region defined in HTML code with height and width attributes
 JavaScript code may access the area through a full set of drawing functions
Example:
<canvas id="example" width="200" height="200"> This text is displayed if your browser does not support HTML5 Canvas.
</canvas>

6. WebGL 1.0 is based on OpenGL ES 2.0
It uses the HTML5 canvas element 
WebGL does not have the fixed-function (Like OpenGL ES 2.0, )
Shaders in WebGL are expressed directly in GLSL

7. WebGL is widely supported in modern browsers
dependent on other factors like the GPU supporting
Test Page For Support :

8. WebGL has not only been used in 3D web design and gaming
Use by some researchers for scientific purposes
For example :
NASA developed an interactive web application called Experience Curiosity to celebrate the 3rd anniversary of the Curiosity rover landing on Mars

9. The WebGL API may be too tedious to use directly without some utility libraries
JavaScript libraries have been built to provide the additional functionality
Libraries :
A-Frame (VR)
BabylonJS
 three.js
 O3D
 OSG.JS
 CopperLicht