What is UCAS?

The Universities and Colleges Admissions Service (UCAS) is a UK-based organisation whose main role is to operate the application process for British universities.

Who Can Take UCAS?

All students planning to study for an undergraduate degree in the UK must apply through UCAS – including home students (generally British and EU students) and international students (non-EU).

Application Procedures

1) Register and fill in personal details
2) Additional information (UK applicants only)
3) Student finance (UK and EU applicants only)
4) Course choices – You can chose up to five courses to apply to, in no order of preference.
5) Full education history
6) Employment history
7) Write a personal statement
8) View all the details
9) Get a reference, pay your application fees and submit application

Step-by-step guide from UCAS
https://www.ucas.com/sites/default/files/how-to-apply-guidance.pdf