Introduction to drawing 2D graphics on the web with the Canvas API.
The Canvas API provides a powerful way to draw graphics, animations, and games on a web page using JavaScript. It works with the `<canvas>` HTML element, which creates a fixed-size drawing surface. By itself, the `<canvas>` element is just a blank rectangle; all the drawing is done via JavaScript. To draw on the canvas, you first need to get its 'rendering context'. For 2D graphics, this is done with `canvas.getContext('2d')`. This context object is what provides the methods and properties for drawing. You can draw simple shapes like rectangles (`fillRect`, `strokeRect`), lines (`moveTo`, `lineTo`, `stroke`), and arcs/circles (`arc`). You can also control colors, styles, and transformations (like moving, rotating, and scaling the drawing surface). The Canvas API is a lower-level API compared to SVG (Scalable Vector Graphics). It is raster-based, meaning you are drawing pixels on a grid. Once something is drawn, the canvas doesn't remember what it was; it's just a collection of pixels. This makes it very fast and suitable for complex scenes with thousands of objects, like in games or data visualizations, but it also means you are responsible for manually redrawing the scene whenever something changes.