The Galactic Center is of course the very center of our galaxy, the Milky Way. It is located at 26 degrees Sagittarius, with a definite orb of 2 degrees and affectively even a few degrees further. Exactly at this center is a super-massive black hole. Black holes have such incredible mass that they also have a super-massive gravity field; they suck in.
Our Galactic Center (GC) black hole also puts out. It radiates strong radio waves. Because of the orb of the GC it has been postulated that the Moon does not have a void of course phase when exiting Sagittarius.
Planets aspecting the GC and the house in which the GC falls are energized by this massive force. It strengthens their importance in a chart. A heightened sensitivity is also associated with those whose placements resonate with the GC.
Do you have planets at the GC or in aspect?