It means that the point (6,2) is on both graphs at the same time. In short, it is the intersection point of the two graphs.
Algebraically, the ordered pair (x,y) = (6,2) makes all of the equations in the system to be true equations. A true equation is one where it simplifies to have the same number on both sides.
A system with at least one solution is considered a consistent system. If there is only one solution, then the system is also considered independent.