I had just moved into a new home.  The house had been empty for quite a few years.  As a result, there was a lot of remodeling to do.  One of the first things I decided to do was paint the living room walls.  The walls were currently painted an ugly yellow and the paint was peeling.  I went to the paint store and looked over the paint colors.  I settled on a calming blue.  I figured out how much paint I would need by calculating the area of the room, then I bought enough gallons to cover the job.  I left the store and loaded the paint and supplies I bought into my car.  After getting home, I spread a plastic drop cloth over the floor and got the paint ready.  I took a brush and dipped it in the paint and spread it over the wall.  This was going to look much better! 
Question: Did they use a paint brush or roller?
They used a paintbrush