That means a lot, so I'll do my best! 'Kin is an umbrella term, used to mention three 'kin types: Otherkin, Therianthrope/Therian, and Fictionkin.
Otherkin: “identifying nonphysically as something other than human, partially or wholly.” : Example, being dragonkin.
Therianthrope/Therian: "someone who nonphysically identifies specifically as an animal that exists or used to exist physically on this earth" : Example, being wolfkin, or dinosaurkin. While the definition is a bit under works as therians determine whether they focus on the basis of the animal, or just the animalistic experiences, it's a good place to start.
FIctionkin: “identifying nonphysically as a fictional character and/or species, partially or wholly.” : Example, hobbitkin, or a Steve Rogers kin.
While these are different, there is one important similarity between all three of them: it's involuntary. One can't *choose* to be 'Kin, nor a specific type. You either are what you are, or you're not. I've grown to know of many otherkin who actually Don't Like Their KinTypes.
(I'm going to leave it at this for now, and you can ask me as many questions as you'd like c:)