The Mercator projection is a cylindrical map projection created by the Flemish cartographer Gerardus Mercator in 1569. It represents lines of constant course, known as rhumb lines, as straight segments, making it useful for marine navigation. However, this projection distorts the size of landmasses, especially near the poles, making them appear larger than they are. Despite its distortions, the Mercator projection remains popular for world maps and online mapping services due to its ability to maintain angles and shapes. It is particularly effective for equatorial regions, where the distortion is minimal, providing a practical tool for various applications.