When watching the below clip in the final approach sequence we can clearly hear setting flabs to 1, 2 and then to maximum.
At 12:05 into the clip, when fully landed plane is rolling through airport, FO says that flaps are set to 1. As I understand, they were changed from "max" to "1" a moment ago.
What is the reason of moving the flaps when plane is rolling after landing? Does it affect anything?
I am a total theoretical noob to the flying, but I was always more than sure that flaps are used to modify the lifting force of the wings (that's why they're set to "max" during final approach, to extend wings and its lift to maximum).
So, what am I missing?