question: BACKGROUND Understanding basic epidemiology and public health concepts is essential to the provision of safe care during a pandemic. These basic concepts and terms include containment, mitigation, predictive modeling, latent period, incubation period, reproduction number, case fatality rate, and test sensitivity and specificity. OBJECTIVES Public health concepts and terms are defined, described in the context of the COVID-19 pandemic, and specific implications for oncology nursing practice are discussed. METHODS A review of public health literature and reputable websites with a focus on COVID-19 data. This article defines epidemiologic and public health concepts and uses examples from the pandemic to illustrate oncology nursing implications. FINDINGS The COVID-19 pandemic is changing oncology nursing care delivery. Oncology nurses need to understand these concepts to anticipate and advocate for optimal oncology care.