Spray drying is a widely utilized technique for converting liquid or slurry feedstocks into dry powders by rapidly drying with a hot gas. It is extensively used in the food, pharmaceutical, and chemical industries due to its ability to preserve heat-sensitive materials and produce particles with specific characteristics. This paper reviews the fundamental principles, equipment design, process parameters, and recent innovations in spray drying technology. Applications in various sectors are discussed, along with challenges related to thermal degradation, powder agglomeration, and process efficiency.