your school
Honorific term used to refer respectfully to the listener's or reader's school. Common in formal letters, speeches, and business communication.
I sincerely hope to be admitted to your school.
I wish your school continued prosperity.
I was deeply impressed by your school's educational policy.
I am applying with your school as my first choice.
I wish for the continued growth of your school.
貴校 respectfully refers to the listener's school, while 本校 is the humble/neutral way a school refers to itself.
Compound of 貴 (ki, 'noble; your') and 校 (kō, 'school'). The prefix 貴 is a common honorific in formal terms like 貴社 (your company) and 貴国 (your country).