is the second person, familiar plural in Spanish.
meaning of vosotros
Vosotros is you-all (plural) informal, not formal. Yes, it is used mostly in Spain, but that shouldn't mean that you ignore it. Though you might not wish to give it the priority that you do the formal construction, you should be able to recognize it when you see it
tu hablas (you speak) vosotros (used only in Spain) (you-all speak)
usted habla (you speak) ustedes hablan (you-all speak)
el habla (he speaks) ellos hablan (they speak)
ella habla (she speaks)