What is Yuri? Put simply, it’s one of the gay genres in anime.
Yuri (also known as Girl’s Love ガールズラブ) is a genre in anime, manga, and other fictional types of media originating from Japan. It focuses on the romance and often sexual relationship between two women. Please note, this term is only used to refer to the genre, it is not used to describe gay couples in Japan.
This genre was originally aimed at the female audience, but over time it has become more male oriented. Many Yuri anime and manga often have a lot of fan service as opposed to romantic story-telling. Of course, there are still Yuri anime and manga that will focus on romance in addition to, or instead of, the sexual aspect of the relationship.
The counter-part to Yuri is known as Yaoi. Yaoi focuses on the romance between two men.
And that’s all you need to know about the Yuri genre! You can find more information on subculture terms just like this in my growing Otaku Encyclopedia.