Latitude and longitude lines are a coordinate system on the earth's surface, which is drawn to determine position and direction on the earth. The meridian and latitude lines are perpendicular to each other, forming a coordinate grid.
The meridian indicates the north-south direction and is the starting line for all east-west directions on Earth. The parallels indicate the east-west direction and are the starting line for all north-south directions on Earth. The latitude and longitude lines on the earth are a closed circle, the meridians divide the whole earth into two semicircles, and the parallels form a circle.
The significance of the latitude and longitude line is that it allows the position of the earth's surface to be precisely located, thus providing a reliable basis for navigation, aviation, geographical research and other activities on the earth. In addition, latitude and longitude also provide a reliable time standard for people on the planet, so that people can better grasp the time and better organize their schedules.
The line of latitude is the line centered on the equator and dispersed from the equator to the poles. Lines of latitude indicate the east-west direction, i.e., they are horizontal. The latitude ranges from 0 degrees at the equator to 90 degrees to the north and south poles. This means that the total number of lines of latitude on the entire Earth's surface is 90, 45 each in the Northern Hemisphere and the Southern Hemisphere.
The line of longitude is a line that starts from the prime meridian (through the Greenwich Observatory in the United Kingdom) and extends from east to west. Longitude lines indicate the north-south direction, i.e., they are perpendicular. Longitude ranges from 0 degrees on the prime meridian to 180 degrees to the east and 180 degrees to the west. Thus, the total number of longitude lines on the entire Earth's surface is 360, with 180 each in the Eastern and Western hemispheres.
Overall, the difference between the line of latitude and the line of longitude is their direction and starting point. The line of latitude indicates the east-west direction, while the line of longitude indicates the north-south direction. Also, the line of latitude is centered on the equator, while the line of longitude is centered on the prime meridian. These differences give latitude and longitude their own unique uses and importance in geolocation, navigation, and surveying.