Afoxé (ah-fo-SHEH) is basically candomblé with the religion taken out...the use of candomblé rhythms and "songs" in social, non-religious settings like Carnival and weekly dances.  The principal rhythm associated with afoxé is ijexá (ee-zheh-SHAH), a more subtle and complicated version of what you might hear pounded out on the Maxwell House coffee can for a late-hours Manhattan cocktail party conga line (a simplified midi version is here as an example).  On terreiros de candomblé ijexá is associated with Oxalá (the father) and Oxum (goddess of sweet waters).

Embaixada Africana (African Embassy) was the first afoxé, parading in the Carnival of 1895.  The next year afoxé Pândego da África (African Hijinks) went out, and in 1905 an afoxé climbed the Ladeira da Barroquinha to parade up the Ladeira de São Bento, thereby breaking a tacit understanding that the Carnival groups from the lower (and darker) economic classes had their areas (Baixa dos Sapateiros, Barroquinha, Pelourinho) and the upper classes had theirs (Avenida Sete de Setembro, Piedade).  Salvador's largest and most widely known afoxé -- Filhos de Gandhy -- was formed in 1949 by a stevedore whose inspiration was the great Indian leader and pacifist (who had been assassinated the year before).  Other afoxés include Filhos de Korin Efan, Badauê, and Filhas de Oxum.

Listen to Afoxé Filhos de Gandhy  

Blocos Afros are Carnival blocos (groups) which, put simply, celebrate cultural manifestations of African origin.  The rhythms are African -- though usually not ijexá -- and the dress is African-inspired (in contrast to afoxé Filhos de Gandhy, whose robes draw their inspiration from the Indian subcontinent).  Olodum, Ilê Aiyê, and Ara Ketu are the three biggest and best-known blocos afros...Ara Ketu -- and in international terms Olodum to an even greater degree -- having achieved significant commercial success.  Other blocos afros include Muzenza (from Liberdade), and Malê de Balê (of Itapoan), who drew the inspiration for their name from the Malê Revolt.

Listen to Bloco Afro Ilê Aiyê