The Mercator projection is a cylindrical map projection created in 1569 that is conformal, meaning it preserves angles and shapes at the expense of distorting area, especially near the poles. This distortion makes it useful for navigation because straight lines on the map represent lines of constant compass bearing (rhumb lines). While it is the standard for online maps, it exaggerates the size of countries like Greenland, Antarctica, Canada, Russia, USA making them appear much larger than they are relative to equatorial regions.