That's for clearing that up. Can I ask though, why would you need a fiance visa if you could just obtain a spousal visa upon marriage?
It depends on your situation.
A fiance visa is for people currently living outside the UK who wish to marry in the UK and then settle there with their British spouse. In order to marry in the UK, they will need a fiance visa, which lasts for 6 months and is applied for outside the UK (you cannot get one from within the UK) - they must marry within those 6 months and then switch to a spousal visa after the wedding. However, if they get married outside the UK first, they can just apply for a spousal visa from their home country and bypass the fiance visa altogether.
If you are already in the UK on a student or work visa, then you don't need to get a fiance visa to come to the UK (because you are already here). However, if you wish to marry in the UK while on that student/work visa, you will need to get a CoA (Certificate of Approval) to do so. Once you are married, you can then switch to a spousal visa, without having to get a fiance visa first.