Think about your character's backstory and answer as many of the following questions as you like:
1) How much of the character's backstory did you know when you started to play them?
Not a whole lot, but enough to get a good sense of who she was and why she is the way she is.
2) How specific or vague do you tend to make a character's background? Why?
I tend to be pretty specific on certain things, but I don't need to know what their favourite food when they were 10 was or anything like that. Major events, etc. all that stuff is necessary.
3) What purpose do you feel backstory serves?
People aren't who they are without their past, so if I'm trying to create a realistic character, then I need that information to understand their motives, even if it's knowledge only I as the player have.
4) What have you learned from your character's backstory?
She is so damaged. The more I think about it, the more I realize just how screwed up she really is.
5) Is it difficult to play with a character who has little/no backstory? Why or why not?
That depends on the character/game/setting/etc. Crack characters generally don't need backstory. The characters that really stick with me, I need that information.
6) For canon characters: How do you fill in the gaps canon leaves in your character's backstory? How do you explain to those unfamiliar with your canon what a character's backstory is?
I take hints from what canon has given me and expand from there in what I think is a logical and reasonable fashion.
7) For original characters: How much world building do you do in your character's backstory? Do you establish an entire family / community society in the process of telling your character's history?
Probably not a lot. I do have a vague idea of where they're coming from and what the "rules" of their worlds are, but I don't go into major detail. One aside, and then yes, I went whole hog, but she's based in an established fandom, so that made it a bit easier.
8) How much research / work have you put into your character's backstory so far? Are you finished, or is it an ongoing process?
It's usually an ongoing process, because there's always something that comes up that I haven't addressed yet, or I need to put more detail into and then it's back to research. Which I do do, because I try to make my major characters as realistic to their situations as possible.