I used to have the biggest collection of Barbie dolls when I was a wee lad.
what type of doll is Barbie dolls?
Barbies are a fashion doll created by Mattel.
what are they used  for?
doll and her lifestyle.
Mattel has sold over a billion Barbie dolls, making it the company's largest and most profitable line. However, sales have declined sharply since 2014. The doll transformed the toy business in affluent communities worldwide by becoming a vehicle for the sale of related merchandise (accessories, clothes, friends of Barbie, etc.). She had a significant impact on social values by conveying characteristics of female independence, and with her multitude of accessories, an idealized upscale life-style that can be shared
What's Her Face (doll)
What's Her Face was a line of customizable dolls that straddled the line between traditional fashion dolls and creative activity toys. Made by Mattel, the line ran from 2001–2003, and enjoyed only a modest success in a market dominated by Mattel's iconic Barbie and MGA Entertainment's Bratz dolls. Following the discontinuation of the What's Her Face line, their body molds were used for the Wee 3 Friends line of Barbie-related dolls. Several fashion, wig, and activity packs were