An SVG introduction demonstrates basic shape drawing within an HTML page, featuring rectangles, circles, a polygon, and a line rendered directly via SVG markup. The example uses raw SVG elements like `<rect>`, `<circle>`, `<polygon>`, and `<line>` with CSS styling properties for fill, stroke, opacity, and rounded corners. No external libraries are used; the visualization relies solely on static SVG attributes and inline styles, showcasing fundamental vector graphics capabilities in a React-agnostic HTML context.