This chapter provides a concise overview of enteral and parenteral nutrition in clinical and public health settings. It begins by exploring various types of enteral feeding methods, including nasogastric, nasojejunal, and percutaneous endoscopic gastrostomy (PEG) tubes. It then discusses both indications for enteral nutrition, such as dysphagia and prolonged inadequate oral intake, and contraindications, such as intestinal obstruction and severe gastrointestinal bleeding. An analysis of enteral feeding formulas follows, covering standard polymeric, elemental, semi-elemental, and disease-specific options. This chapter addresses common complications associated with enteral feeding, including mechanical issues, gastrointestinal disturbances, and metabolic imbalances, along with strategies for their prevention and management. The focus then shifts to parenteral nutrition, outlining its indications (e.g., severe malabsorption and bowel obstruction) and contraindications. A key section details the nutritional requirements for parenteral nutrition, guiding calculating energy needs and determining appropriate macro- and micronutrient distribution for various patient populations. Throughout, this chapter emphasizes the importance of individualized nutrition care plans, regular assessment, and taking a multidisciplinary approach to managing patients receiving enteral or parenteral nutrition. By offering a comprehensive yet concise overview, this chapter equips healthcare professionals with essential knowledge for effectively implementing and effectively managing these critical nutritional interventions.