TWO ISOLATED CHARGED METALLIC SPHERES OF RADII R1 AND R2 HAVING CHARGES Q1 AND Q2 RESPECTIVELY ARE CONNECTED TO EACH OTHER THEN THERE IS :

There is Flow of charges from one sphere to another so that both spheres are at same potential. If potential of r1 is greater then charge flows from r1 to r2, until they become same or r2 is greater then vice versa. Hope it clears your doubt.