Jawas are miniscule little creatures that live on Tatooine, and they enjoy scavenging for spare parts and droids amongst the planet's barren plateus. They travel around in huge, pathetically slow sand crawlers that are always breaking down, and are the namesake for the hugely popular Jawa Juice.
They once tried to bully R2-D2 but he kicked all their asses and went home with C-3PO in tow. The Jawas they worshipped R2-D2 as a god and painted all their crawlers blue to honor him.
Jawa's like to go 'Uteenee!' and make other pointless noises, despite the fact that they can apparently speak perfect English. However, it could simply be that the pointless noises translate into words that, somehow, everyone else can understand. Hmm.