护理学是自然科学、社会科学、人文科学等多学科相互渗透的一门综合性应用学科。从1860年南丁格尔创办第一所护士学校——南丁格尔护士训练学校（Nightingale Training School for Nurses）起，护理学经历了四个过程：简单的清洁卫生护理、以疾病为中心的护理、以病人为中心的整理护理、以人的健康为中心的护理。护理学通过不断地实践、教育、研究，得到积极充实和完善，逐渐形成了自己特有的理论和实践体系，成为一门独立的学科。

Nursing is a profession within the health care sector focused on the care of individuals, families, and communities so they may attain, maintain, or recover optimal health and quality of life.

Nurses may be differentiated from other health care providers by their approach to patient care, training, and scope of practice. Nurses practice in a wide diversity of practice areas with a different scope of practice and level of prescriber authority in each. Many nurses provide care within the ordering scope of physicians, and this traditional role has come to shape the historic public image of nurses as care providers. However, nurses are permitted by most jurisdictions to practice independently in a variety of settings depending on training level. In the postwar period, nurse education has undergone a process of diversification towards advanced and specialized credentials, and many of the traditional regulations and provider roles are changing.