The scandal first emerged in the McLaren Report, which alleged more than 1,000 Russian athletes partook in or benefitted from a state-sponsored cover-up for athletes using performance-enhance drugs (PEDs).
The second part of the report was published after the Rio Games in 2016. A subsequent International Olympic Committee (IOC) investigation resulted in the Russian Olympic Committee being barred from the 2018 Winter Olympics. The nation's flag won't appear during the opening ceremony, and government officials are not allowed to attend the Games.
If they're banned, why are Russians competing?
Despite the ban, which came down in December, the IOC decided to allow Russian athletes with no history of doping to compete. Though, they aren't allowed to compete under the Russian flag. Those athletes will compete as an Olympic Athlete from Russia.