There are two different funding methods for Crowdfunder projects.
1. Keep what you raise (or flexible funding) – Keep all of your pledges, whether your project hits target or not. This is best suited for causes or charitable projects who can make use of any funds raised. You will not be able to extend your project beyond the initial close date.
2. All or nothing – You will only receive your pledges if you hit your target. This is best suited for projects that need to reach a set target to be able to carry out their aims. You will be able to extend your project if you have not reached your target by the end date.
'Keep what you raise' means that you’ll keep all the money pledged by your supporters, but you’ll also have to fulfil all of the rewards people have pledged on, no matter how much or little is pledged in total.
'All or nothing' means you do have to hit your target by the closing date or your supporters will be refunded and your project will close unsuccessfully.