The javascript canvas is a 2D display widget avaliable on Firefox, Safari, and Opera. The is are plugins that make the widget avaliable for IE. Placing a canvas in a web page is almost identical to placing a picture the <canvas> element requires 3 attributes: height, width, and id. Placing a canvas results in a blank rectangle of the specified hieght and width. All drawing on the canvas is done with a javascript calls. 
 
The canvas 2D api is quite advanced and has support for the following operations. 
 
Canvas State Methods 
 
* restore - restore canvas to last saved state 
* rotate - rotate the coordinate space 
* save - save the canvas state 
* scale - scale the cordiante space 
* translate - translate the cordinate space 
 
Working With Paths 
 
* arc  
* arcTo 
* bezierCurveTo 
* beginPath 
* clip 
* closePath 
* lineTo 
* moveTo 
* quadraticCurveTo 
* rect 
 
Stroking a Path 
 
* stroke 
* strokeRect 
 
Filling an Area 
 
* clearRect 
* fill 
* fillRect 
 
Creating Gradient and Pattern Styles 
 
* addColorStop 
* createLinearGradient 
* createPattern 
* createRadialGradient 
 
Drawing an Image 
 
* drawImage 
* drawImageFromRect