Jawas are small creatures whose faces are obscured by the cloaks that they wear. They are found on Tatooine as nomadic scavengers or working for Jabba, the Hutt. Their faces are never revealed. When the film was made, children of some of the cast and producers stood in as Jawas.
Jawas survive by scavenging whatever they can find and then selling it for any profit that they can. In Star Wars IV - A New Hope, they come across C-3PO and R2-D2 which they sell to Lars and Beru Owen who look after Luke Skywalker.