Iw ould say that. permutation is done when things are same.
Suppose you have 3 red balls and you would like to place them in three holes.
Whatever you do they would look like the same. But you can definately place them in 6 ways
In case of combination things that are to be distributed are not the same.
Suppose you have 3 balls blue green and red.
Now you have to place them in 3 different holes.
You can have 6 combinations. Right?
But with 3 same balls you would get only 1 combination.
Combination takes care by dividing the permutation with the number or repetitions that occur.
I would give you another example.
Suppose you have 4 balls. 2red and two blue.
Now you have to place them in 4 positions.
Had there been 4 different balls tha answer would have been 4!=24.
But Two balls are same.
And hence there is repetioin of some sequence.
Therefore we divide the number by the number of repetion that will take plae.
2 For red and 2 for blue.
Answer would be 6.
I hope I have cleared your doubt.