cram school; preparatory school for entrance exams
A private school that prepares students for entrance examinations, typically for high school or university. Often used in contrast to regular school education.
He is attending a cram school to prepare for university entrance exams.
Tuition at cram schools tends to be expensive.
予備校 is a broader term for any preparatory school, while 受験予備校 specifically focuses on entrance exam preparation.
塾 is a general term for private tutoring schools, which may include exam prep but also cover regular school subjects and enrichment. 受験予備校 is more narrowly focused on exam strategies and intensive preparation.
Compound of 受験 (taking an examination) and 予備校 (preparatory school).