

In an AP, the common difference between any two consecutive number is always same.
Example: 1,3,5,7,9...........
Common Difference (d) = 3-1 = 5-3 = 7-5 = 9-7 = ........... = 2
In a GP, the common ratio between any two consecutive number is always same.
Example: 2,4,8,16,..........
Common Ratio (r) = 4/2 = 8/4 = 16/8 = ...............= 2
