Simplify polygons without creating slivers

When you download geographical data the polygons are often highly detailed, leading to large file sizes and slow processing times. Often this detail is unnecessary if you’re not intending to produce small–scale maps. Most thematic maps, for example, tend to compare large geographies such as nations or regions, so the detail is unnecessary. Likewise, if you’re producing your map for use on the web, for example as an interactive visualisation, too much detail can slow the rendering and responsiveness of your app.