The International Date Line is located along 180° longitude. It is an imaginary line that runs from the North Pole to the South Pole and separates two calendar dates. When you cross the International Date Line from west to east, you lose a day, and when you cross it from east to west, you gain a day.
The Standard Meridian is the line of longitude that passes through Greenwich, England. It is the prime meridian, and it is used to calculate time zones around the world.
The Equator is the line of latitude that divides the Earth into the Northern and Southern Hemispheres. It is 0° latitude.
The International Date Line is not located along any of these lines. It is located along 180° longitude, which is halfway around the world from the Prime Meridian.