The six major characters are:
Othello - Moorish general beloved by the royalty of Venice until he woos Desdemona, Brabantio(a nobleman)'s daughter when some of them turn against him.
Iago - Othello's loyal right hand man (on the surface) and his worst enemy underneath. Angry at being passed over for promotion, a genius at manipulation
Desdemona - Othello's girlfriend then wife, completely and totally devoted to Othello
Cassio - Othello's lieutenant, promoted over Iago, darling of the Venetians as he is of noble birth
Roderigo - Iago's stooge, wants to be with Desdemona but can't pull it off, funds much of Iago's plans
Emilia - Iago's wife, knows her husband and is the first to see through all the plots