A tutorial demonstrates basic D3.js selection and DOM manipulation using a static HTML page with car listings and paragraphs. The code uses `d3.select` and `d3.selectAll` to change text colors—turning headings blue, list items magenta, and paragraphs green—and to style nested table cells with cyan backgrounds. Data binding via `.data()` maps an array of numbers to blank `h2` elements, while class-based selectors color warning and error messages. All styling is applied through D3's `.style()` and `.text()` methods on the live DOM.