@InspectorCaracal the general consensus seems to be that it is a non-human animal character that represents you, or is controlled/owned by you, in some way.
it can literally be you, just be a small part of you, be some sort of mask/costume you put on to temporarily escape being you/something you live vicariously through, or even just...something you like to show others and say "that's my fursona" without any strong personal connection or any further interaction with it