Understanding the canvas coordinate system is essential for precise drawing and animation. On an HTML canvas, the coordinate system defines how you specify the position of shapes, lines, and images. The origin, or point 0,0, is located at the top-left corner of the canvas. The x-axis extends horizontally to the right, while the y-axis extends vertically downward. Every position you specify is measured in units of pixels, which are the smallest addressable elements on your display.

The coordinates you use are always relative to the canvas itself. For example, if your canvas is 300 pixels wide and 150 pixels high, the bottom-right corner has the coordinates (300,150). If you try to draw outside these bounds, your shapes will not appear on the visible canvas. This pixel-based system means that every value you provide for x and y directly corresponds to a physical pixel location on the canvas, making positioning predictable and straightforward.