Longitude is the lines that run from the North Pole to the South Pole. Also known as meridians, 0 degrees longitude is the Prime Meridian. The Prime Meridian runs through Greenwich, England.
E for East, and W for West, that is after the degree symbol, shows you whether the location is East or West of the Prime Meridian.

On the opposite side of the Prime Meridian (other side
of the Earth) is 180 degrees longitude, also known
as the International Date Line.

The International Date Line is an imaginary line. It is approximately the 180th meridian. The reigons on the east of it are considered one day earlier on their calanders then the regions on the right.

In the above picture, it shows
the International Date Line (the red line).

The picture above is showing you
the lines of longitude (meridians).

This video shows you what the
Lines of Longitude are.

By: Haley Crispell and Cynthia Cheng