This interactive world map demonstrates the use of three projections: Mercator, orthographic, and Albers USA, though the default view is orthographic. Users can drag to rotate the Earth and zoom with the mouse wheel. Clicking on countries switches between projections, with the United States triggering a Mercator projection. The code employs `d3.geoPath`, `d3.geoGraticule`, and `topojson.feature` to render country boundaries from the world-atlas dataset, including dynamic updates on projection changes.