There are two main types of mops - wet mops with absorbent heads for cleaning with water and detergent, and dry mops called dust mops that use strings to pick up dust and lint from floors. The swiffer, invented in 1999, established itself as an innovative cleaning system and pop culture icon, appearing in movies, on Saturday Night Live, and in magazines like Rolling Stone. Mops have evolved significantly over the years to make cleaning floors easier.