Difference between WGM and GM

Can someone explain to me what exactly is the difference between the WGM and GM title? I always thought that it is simply gender related, i.e. woman as grandmaster -> WGM and man -> GM but in the table of the European Women's Blitz Championship some women are now shown with the GM title

Can someone explain to me what exactly is the difference between the WGM and GM title? I always thought that it is simply gender related, i.e. woman as grandmaster -> WGM and man -> GM but in the table of the European Women's Blitz Championship some women are now shown with the GM title