Earth 1

Earth 1 is the main earth in the multiverse that is home to Barry Allen and James. It was named by James after being asked by Jason Allen what his earth was called. After the Siege of the United Nations Barry Allen and Jay Garrick travel to earth 1 to recruit a kid with potential as stated by Barry.

Earth 1 is important in that its a central junction in the multiverse, being the middle intersection from which one could travel to any other alternate Earth.