Rabbi Meir said that a job started before the 14th day could be completed on the 14th. But the Sages say that this permission applies only to the following three crafts: tailors, barbers, and launderers. Why these? Tailors - because even during the seven days of Passover, sewing will be allowed if done non-professionally. Barbers and launderers - because even during the Holidays, people who just returned from an overseas journey or who just got out of prison would be allowed to be cut their hair and launder their clothes.
Today, in the absence of the Passover sacrifice, these limitations are largely removed, although it is still recommended to spend the 14th preparing for the Passover holiday.
Art: Chardin. The Laundress. 1733