In context of BL:
**__BL (Boys Love):__**
A genre of romance centered around the romance between two male characters. The term is a translation of “Shōnen-ai” and is generally regarded as an umbrella term for gay romance of Asian origin (especially SE Asia). It is original content that is easy to read and written for the masses/public.
It has largely been criticized as being written by and for presumably straight women – however, recent research has been criticizing this view. This content is generally considered to include sexual content (various age ratings are present to help distinguish if explicit content is present) and a clear distinction between a masculine top and a feminine bottom in the relationship.
**__Yaoi:__**
While English audiences tend to use "Yaoi" and "BL" interchangeably, Japan largely uses "Yaoi" to describe fanfiction creations, especially those of short form, little to no plot, and graphically sexual nature. Like BL, this is largely considered to be written by and for presumably straight women.
**__Shōnen-ai:__**
Often considered, especially internationally, to be gay romance with a heavy focus on plot/story without explicit scenes. However, this is not the full story. This is a genre, evolved from "Tanbi," focused on the romance between young teenage boys.
**__Tanbi:__**
Perhaps the earliest distinct genre focused on gay romance. These stories were written for the appreciation and pursuit of beauty (language and storyline) and was characterized by flowery language, uncommon diction/word choice, and was generally considered difficult to read. This genre evolved into "Shōnen-ai" and "BL", and is no longer really written itself.
**__Bara (Mens Love or ML):__**
A genre of gay romance largely written by and for gay and bisexual men. Contrasting with the more popular "BL" genre, "Bara" works do not tend to lean into the same conflicts; they tend to steer away from political themes, “beautiful” boys, and masculine top/feminine bottom dynamics. This work is also largely explicit in nature, sometimes even going into toxic violent masculinity, and features autobiographical themes.
In international circles, this term has been more broadly used to refer to gay media featuring very masculine men (such as beefcakes and bears).
**__Y-Series:__**
Thai dramas portraying gay romance, derived from the term “Yaoi” and heavily influenced by Japanese BL works.
**__Danmei:__**
Chinese gay romance genre that is largely adapted/inspired by "Tanbi" – with both names meaning the same thing.
**__MLM, MxM, M/M:__**
Ways to write that a romantic/sexual relationship exists between two men/males. Men Loving Men. Male x Male. Man/Man. Etc.
**__Achillean:__**
A term describing men/masculine-presenting folks, and media portraying them, who like other men/masculine-presenting folks – either exclusively or non-exclusively. This term, referring to the historical figure Achilles, is considered to be modelled after the popular usage of similar term “sapphic” in WLW circles.
🧐 *Note: There is a good deal over grey territory, overlap, crossover, and evolution in these terms. And their usage, connotations, and history is further complicated by their adaptation/usage in international circles.*