This document provides an overview of fundamentals of radiation protection including: - Atomic definitions such as isotope identification, activity, and half-life. - Common types of radioactive decay including alpha, beta, positron, and gamma emissions. - Units used to measure radiation exposure such as becquerel and curie. - Key factors that reduce radiation exposure including distance, shielding, and time. - Biological effects of radiation exposure and typical annual radiation doses from various sources. - Regulations for radiation exposure limits set by organizations like the ICRP.