GamerGate is a very big argument or dispute that started in 2014 between people who play video games or games on the Internet.
Some people felt upset and angry about how women and minorities were sometimes treated in the game industry. They believed the gaming industry was not treating everyone fairly and that women and minorities were not getting the same chances as others.
Others thought that the people who spoke up about these things were trying to ruin video games or were trying to promote their own agendas. Some people even sent threats and hate messages to these people.
So it became a very big and heated argument that lasted for a long time.
Basically, some people wanted to make sure that everyone was treated fairly in the gaming industry and others disagreed and it caused a lot of controversy and drama.