This example shows a simple 2x2 grid of circles, each with a solid color, demonstrating basic SVG rendering on a plain HTML page. The graphic uses four circle elements positioned via inline `cx` and `cy` attributes, with one circle using the default black fill and the others explicitly set to red, blue, and green. The code relies on native SVG within an `index.html` file, with no JavaScript logic or external data source, highlighting how static vector shapes can be created directly in markup.