It means Artifact is made based on Dota 2 Universe. Many features in Artifact share the same concept with Dota 2, and most importantly, most of the cards including items, abilities, and heroes are from Dota 2.
So kinda like Hearthstone and Warcraft?
A few weeks back, I read a post regarding Richard Garfield's decision on making Artifact a Dota based card game. https://moot.us/lounges/56/boards/209/posts/283611And also, the article within the post is worth a read.https://techraptor.net/content/artifact-developer-interview-why-they-chose-dota-how-it-influenced-a-card-game-and-artifacts-standout-features