This chapter offers a comprehensive overview of electrospinning, a versatile technique for fabricating nanofibers with exceptional properties. It delves into the intricate mechanisms governing fiber formation, emphasizing the importance of understanding these processes to optimize fiber characteristics. The chapter discusses the influence of polymer solution properties, processing variables, and environmental conditions on fiber morphology and performance. It explores innovative strategies for creating hierarchical nanostructures, primary and secondary structures, which significantly enhance the functional properties of nanofibers. Post-modification techniques, including chemical modification, physical modification, and nanoparticle incorporation, are also discussed further to tailor the properties of nanofibers for specific applications. The chapter highlights the significance of modeling and optimization methods in achieving desired nanofiber characteristics, ultimately enabling their use in various fields, such as tissue engineering, drug delivery, filtration, and energy applications.