They fill a similar narrative role, but they are not the same character. Protoman is from the original MegaMan games, and is Dr. Light’s first humanoid robot (The “First Son of Light”). The “pre-MegaMan”. He mostly went around being cool, soloing stuff, and occasionally helping MegaMan.
Zero is in the MegaMan X series, which takes place “a long time later”. He is one of Dr. Wily’s last designs, who got put into hibernation until the events of MegaMan X, and is one of the central figures in the Maverick Hunters. He mostly went around being cool, soloing stuff, and partnering up with MegaMan X. Also he went into hibernation again and woke up to his own really good game series.
They fill a similar narrative role, but they are not the same character. Protoman is from the original MegaMan games, and is Dr. Light’s first humanoid robot (The “First Son of Light”). The “pre-MegaMan”. He mostly went around being cool, soloing stuff, and occasionally helping MegaMan.
Zero is in the MegaMan X series, which takes place “a long time later”. He is one of Dr. Wily’s last designs, who got put into hibernation until the events of MegaMan X, and is one of the central figures in the Maverick Hunters. He mostly went around being cool, soloing stuff, and partnering up with MegaMan X. Also he went into hibernation again and woke up to his own really good game series.