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.
前提知識 is more strictly 'prerequisite knowledge' required before proceeding, while 予備知識 is broader 'background knowledge' that may be helpful but not always mandatory.
基礎知識 means 'basic/foundational knowledge', often implying a systematic foundation, whereas 予備知識 is more about prior familiarity or preparatory information.
Compound of 予備 (yobi, 'preparatory, reserve') and 知識 (chishiki, 'knowledge'). The word is a straightforward modern coinage with no obscure historical derivation.