This example demonstrates how to begin using D3 version 6, focusing on basic SVG setup and marker definition. The code creates an SVG canvas and defines an arrow marker with a red path, using the `marker` element for reusable arrowheads. It selects the SVG element with `d3.select`. The example includes a YouTube tutorial link in the README, though the visible JavaScript only imports `select` from D3 and selects the existing SVG, showing minimal initialization steps without further interaction or data rendering.