fundamental knowledge; the basics
Refers to the essential knowledge or foundational understanding required in a field, subject, or activity.
It is important to acquire fundamental knowledge in this field.
If you have the basics of cooking, you can make it without looking at a recipe.
基本 is a broader term for 'basics' or 'fundamentals', often used as a noun or adjective, while 基礎知識 specifically refers to foundational knowledge or information.
Compound of 基礎 (foundation, basis) and 知識 (knowledge).