DotA is a moba (mulltiplayer online battle arena) game made by Valve, the same company that's making Artifact

DotA has a rich history and has been one of the most competitive eSports consistently for over a decade

A lot of the thematic design of Artifact is based on DotA, but isn't completely reliant on DotA either. Some heroes or other characters will be released in Artifact before DotA

Richard Garfield, the creator of Artifact, has said he developed the game as a concept before implementing DotA themes into the game, implying that the game does not rely on DotA in anyway, but instead looks to it for inspiration

If you want to learn more about DotA, here are some good resources: