From Undergrad to grad school

I was wondering how graduate school works. So I have already submitted my Intent to register at UC Santa Barbara for Undergrad and was just curious as to how applying to grad school works. If I was already accepted as an undergrad will I have to apply again to continue as a graduate student at this school or no? I know graduate school is a ways away for me but I really am just curious.

completely different application. (And, btw, the UC’s have a reputation of preferring that you go somewhere else for grad school, even another UC.)

Congratulations! You have a long way to go, but unless you are in some sort of a combined program you will have to apply all over again.

Usually, yes. Grad schools have a completely different set of requirements for the application, including UG transcripts, GRE scores (or other standardized tests), letters of recommendation from your professors, research papers (if any), etc.