Summary of Canvas basic knowledge.

• Has only two attributes, width and height
• Can be sized by CSS, be careful about the scales
• Can be styled like normal image (margin, border, background…)
• If no styles applied, it will be fully transparent
• creates a fixed-size drawing surface that expose to 1 or * rendering contexts

<canvas id="tutorial" width="150" height="150"></canvas>

var canvas = document.getElementById('tutorial');
var ctx = canvas.getContext('2d');