Electrospinning is a versatile technique for producing ultrathin fibers. This review provides a comprehensive overview of electrospinning, including its principles, methods, materials, and applications. It begins with an introduction to the history of electrospinning, followed by a discussion of its principles and typical apparatus. The review then discusses the renaissance of electrospinning over the past two decades as a powerful technology for producing nanofibers with diverse compositions, structures, and properties. Applications of electrospun nanofibers include their use as "smart" mats, filtration membranes, catalytic supports, energy harvesting/conversion/storage components, and photonic and electronic devices, as well as biomedical scaffolds. The review highlights recent advances in the applications of electrospun nanofibers, focusing on representative examples. It also offers perspectives on challenges, opportunities, and new directions for future development. Finally, it discusses approaches to the scale-up production of electrospun nanofibers and showcases typical examples of commercial products based on electrospun nanofibers. The review also compares electrospinning with other techniques for producing nanofibers. Electrospinning involves an electrohydrodynamic process where a liquid droplet is electrified to generate a jet, which is then stretched and elongated to form fibers. The process involves four consecutive steps: (i) charging of the liquid droplet and formation of Taylor cone or cone-shaped jet; (ii) extension of the charged jet along a straight line; (iii) thinning of the jet in the presence of an electric field and growth of electrical bending instability; and (iv) solidification and collection of the jet as solid fiber(s) on a grounded collector. The success of electrospinning a polymer solution depends on various parameters, including the polymer's molecular weight, solvent, concentration, electrical conductivity, and ambient conditions. The review also discusses the materials used in electrospinning, including organic polymers, conductive polymers, and natural biopolymers. It highlights the challenges in electrospinning certain materials and the strategies to overcome them. The review concludes with a discussion on the future directions of electrospinning and its potential applications in various fields.Electrospinning is a versatile technique for producing ultrathin fibers. This review provides a comprehensive overview of electrospinning, including its principles, methods, materials, and applications. It begins with an introduction to the history of electrospinning, followed by a discussion of its principles and typical apparatus. The review then discusses the renaissance of electrospinning over the past two decades as a powerful technology for producing nanofibers with diverse compositions, structures, and properties. Applications of electrospun nanofibers include their use as "smart" mats, filtration membranes, catalytic supports, energy harvesting/conversion/storage components, and photonic and electronic devices, as well as biomedical scaffolds. The review highlights recent advances in the applications of electrospun nanofibers, focusing on representative examples. It also offers perspectives on challenges, opportunities, and new directions for future development. Finally, it discusses approaches to the scale-up production of electrospun nanofibers and showcases typical examples of commercial products based on electrospun nanofibers. The review also compares electrospinning with other techniques for producing nanofibers. Electrospinning involves an electrohydrodynamic process where a liquid droplet is electrified to generate a jet, which is then stretched and elongated to form fibers. The process involves four consecutive steps: (i) charging of the liquid droplet and formation of Taylor cone or cone-shaped jet; (ii) extension of the charged jet along a straight line; (iii) thinning of the jet in the presence of an electric field and growth of electrical bending instability; and (iv) solidification and collection of the jet as solid fiber(s) on a grounded collector. The success of electrospinning a polymer solution depends on various parameters, including the polymer's molecular weight, solvent, concentration, electrical conductivity, and ambient conditions. The review also discusses the materials used in electrospinning, including organic polymers, conductive polymers, and natural biopolymers. It highlights the challenges in electrospinning certain materials and the strategies to overcome them. The review concludes with a discussion on the future directions of electrospinning and its potential applications in various fields.