UCAS or The Universities and Colleges Admissions Service is a UK-based organization that operates the application process for universities in the UK. If you wish to study in the UK for your undergraduate degree, you will have to apply through UCAS.

The UCAS is divided into seven main sections: 

1. Personal Details Section, which requires an applicant to fill in basic details such as his/her name, date of birth, phone number, postal address, passport details, and other such personal details.

2. Academic Details Section, which requires the applicant to submit their official 10th-grade mark sheet, 12th grade predicted marksheet, and their official scores on the IELTS or TOEFL. Students may also choose to submit their official SAT/ACT scores, SAT Subject Test Scores and Advanced Placement Exam scores (these scores are not required as a part of your application). 

3. Personal Statement Section, which requires the applicant to write a personal statement with a maximum of 4,000 characters. Applicants must elaborate on the reasons for their choice of course and why they deserve to be admitted to a particular university. 

4. Employment Details Section, which asks the applicant to submit information about all their previous jobs and internships, if any.

5. Universities Selection Section, which requires the applicant to list up to five universities or colleges where they would be applying through the UCAS. It is important to remember that you cannot apply to more than 5 universities through the UCAS.

6. Letters of Recommendation Section, which requires the applicant to submit the contact details of two people who would be writing the letters of recommendation for them. 

7. Payment Section, which requires the applicant to specify how they will be paying their tuition fees. The options might include personal funds, student loans, government funding, or other such mediums. Applicants may also fill in their Unique Learner Numbers if they have one. 

You can create a free Undergraduate UCAS account on the official UCAS website: www.UCAS.com. Also, applicants should make sure that they submit only official school documents with stamps from the issuing authorities. The submitted documents should be in English or submitted along with an English Translation. 

For more information about applying to universities in the UK for an undergraduate degree, please visit unirely.com and get personalized help on filling out your UCAS form.