One of the biggest factors in comparing the two is necrosis, which the T-Virus causes in any infected. While the T-Virus caused the majority of events from the first few games of the Resident Evil series, it was never quite as impressive as the G-Virus.
The G-Virus, also known as Golgotha Virus, is a distinct virus that posed a much bigger threat in the game’s canon. However, the T-Virus was not the only retrovirus that is a descendent of the Progenitor Virus. While there are many T-Virus derivatives in the Resident Evil games, it is itself derived from the Progenitor Virus which is at least hundreds of millions of years old.
The T-Virus was the catalyst that begins the majority of events in the games and is probably the virus most casual fans are familiar with. One of the core staples of the Resident Evil franchise is a viral outbreak of some sort, whether it results in flesh-eating reanimated corpses or supernatural abilities.
