This document provides an introduction to physical quantities, units, and measurement in physics. It begins with definitions of key terminology like physical property, scalar and vector quantities, and standard form notation. It then discusses the International System of Units (SI) including the seven base units, common prefixes, and how to convert between multiples and submultiples of units. The document also covers derived SI units and examples of converting between derived units. It emphasizes the importance of understanding whether a quantity is scalar or vector.