US Transcripts and UCAS

So for the two schools I'm applying to through the UCAS, how will they get a hold of my transcript/do they want a copy? For US schools our guidance counselors submit them through this computer system that obviously won't work through the UCAS. Do they want my transcript or should I find a way to include my grades somewhere else in my application? Also small side question, would you suggest getting a reference from our guidance counselor or a teacher? Thanks!

You submit your grades through UCAS in the right section for your type of grades. Unis usually want to see hard copies when you arrive. The person who you think knows your best and will be able to comment on your ability to do uni level work in your subject should write your ref.