About: Imaginary line
In general, an imaginary line is usually any sort of geometric line that has only an abstract definition and does not physically exist. In fact, they are used to properly identify places on a map. Some outside geography do exist, such as the Mendoza Line, which in baseball divides below-average hitters and extremely poor hitters. A centerline is a nautical term for a line down the center of a vessel lengthwise.
