But along with the innovations made in technology, styles of aprons are better improved and named depending on the type of person who wears the said utilitarian garment. Just like the bistro and the dealer aprons. They could have been part of the waist apron in terms of style. The only thing that makes them differ from typical waist aprons is that bistro apron falls below the knees while dealer aprons are cut above the knees. And since bistro aprons are commonly used by bartenders or baristas, they became more popular as bistro aprons. Same with dealer aprons, this functional outer clothing became part of the everyday uniform of staffs in up market establishments that's why they are called that way.