The Feynman Lecture Series is a set of three books written by physicist Richard Feynman, based on a series of lectures he gave at the California Institute of Technology in the 1960s.
The lectures in Volume 2 build upon concepts and ideas introduced in Volume 1, so reading them in order will provide a better understanding of the material.
While it is possible to understand some of the material in Volume 2 without reading Volume 1, it is recommended to read them in order for a complete understanding.
The Feynman Lectures are written for a general audience and do not require advanced scientific knowledge to understand. However, some background in physics may be helpful in fully comprehending the material.
Each volume covers different topics in physics, so it is not necessary to read all three. However, reading all three will provide a comprehensive understanding of the subject matter.