The document describes 20 different types of nurses and their roles, including registered nurses, cardiac nurses, certified registered nurse anesthetists, clinical nurse specialists, critical care nurses, emergency room nurses, family nurse practitioners, geriatric nurses, perioperative nurses, mental health nurses, nurse educators, nurse managers, nurse midwives, nurse practitioners, nursing administrators, oncology nurses, orthopedic nurses, pediatric nurses, public health nurses, and travel nurses. Each type of nurse has a specialized focus area and set of responsibilities to provide care to patients.