It's primarily finding yourself in a character or finding that character in yourself. Mainly identifying as or with, depending on how high you kin them. It can be mentally, emotionally, or even physically (like phantom feeling). Fictives are exclusive to plurality (don't ask me about them though... I'm not a system). Relating to a character is synpath. There's many other identities i can't explain currently LOL There is an alterhuman and a otherkin wiki that can give more info Compared to lil ol me!
Oh, I actually have the same question. I feel like it is something very personal and that's why it's so hard to explain. However, it seems like people believe to truly be that character like in being in the wrong body or something. I read that otherkin for example believe that they are a dragon, for example, but caged in a human body. In the end, I suppose everybody will have a slightly different explanation for that.
Uhmm okay I'll just use my priv bc it's a lot easier,,
so basically kinning/kin in regular online spaces is just relating to a character, but FICTIONkin is where you heavily identify as that fictional character, think of otherkin but with lilke, idk boss baby or something
fictionkins are NOT irls that's super rude to people with psychosis/a psychotic disorder (i have a psychotic disorder) and feels like a "hey you can't be in this community because you have a psychotic disorder!" which is kinda trash
uhmm there's a lot of info so I would recommend reading this carrd bc it explains the difference between your normal internet user kin and actual fictionkins
im not necessarily a kin (i mean i MIGHT be but i just dont identify with the term due to its community, at most im nonhuman), but i know that its not exclusive to systems, and kinning is a thing outside of fictkinning as well, otherkinity as an example