the inquisitions were tribunals -- a type of trial where the judge (or judges) tries the accused and passes judgment. But these trials were unique in several ways. The accused was required to testify, and he didn't get a lawyer or any assistance. If he refused to testify, the Inquisitor took this refusal as proof of his guilt. Anybody could testify against him, including relatives, criminals and other heretics, and he wasn't told who his accusers were. The accused usually didn't have any witnesses testify on his behalf, because they could also fall under suspicion of being a heretic. He also wasn't always immediately informed of the charges against him.