Seppuku is, in one of its various forms, called junshi, the custom of following a master in death.
Seppuku is a form of ritual suicide in which the so-called 'second' (or decapitator) was either a friend or an opponent wanting to salute his bravery.
Seppuku is, in one of its various forms, called kanshi, the act of making a mortal cut in secret, dressing the wound, and then revealing it to the lord while announcing a protest of the lord's action.
Seppuku is, in one of its various forms, called funshi, a form of suicide whose purpose it was to state dissatisfaction or protest.
Seppuku is, in one of its vairous forms, called jumonji giri, or cross shaped cut, a ritual suicide where there is no 'second' to put a quick end to the samurai's suffering. The samurai was expected to bear his suffering quietly until perishing from loss of blood, passing away with his hands over his face.