These study materials are based on the Edexcel specification for Mechanics 1.
M1 is an introduction to classical mechanics, the set of physical laws governing forces and motion.
It is an essential module for students aiming to study engineering or physics at university, and a starting point for subsequent mechanics modules in your A-level mathematics studies.
If you're just getting started I recommend reading the 'Vectors and motion' topic for an introduction to vectors and the physical quantities used in M1.