The pronoun vosotros (bvoh-soh-trohs) (plural you) is used in spoken Spanish in Spain only. Spaniards use vosotros to informally address a group of people. In all other Spanish-speaking countries, vosotros is taught in the schools, but never used in normal conversation. In Latin America, you hear ustedes; there’s no distinction between formal and informal in the plural you.
Here are all the various you forms using trabajar (to work) as an example:
tú trabajas (you work), which is singular, informal
usted trabaja (you work), which is singular, formal
vosotros trabajáis (you work), which is plural, informal in Spain only
ustedes trabajan (you work), which is plural, formal in Spain, formal and informal in Latin America
You may hear a variation of vosotros in Argentina or Colombia, Vos trabajás (you work). From a grammatical standpoint, this form is totally incorrect, so don’t try to copy it.