noun
background knowledge; prerequisite knowledge
Refers to knowledge one already has or needs before understanding or doing something. Often used in educational, technical, or preparatory contexts.
この講義を受けるには、ある程度の予備知識が必要です。
You need some background knowledge to take this lecture.
予備知識がなくても楽しめる映画です。
It's a movie you can enjoy even without prior knowledge.