A backpack is a versatile and functional type of bag designed to be carried on the back. Typically made of durable materials like nylon, canvas, or leather, backpacks come in various sizes and styles to suit different needs and preferences. They are popular among students, hikers, travelers, and commuters for their practicality and convenience. Most backpacks feature a main compartment for storing larger items such as books, clothing, or electronic devices. Additionally, they often have multiple exterior pockets and compartments to help organize smaller items like keys, wallets, and water bottles. Some backpacks also come with padded laptop sleeves or hydration reservoirs for added functionality. The straps of a backpack are adjustable to provide a comfortable fit for the wearer, and many modern designs include padded back panels and waist straps for added support and weight distribution. Some backpacks even have specialized features like built-in USB ports for charging devices on the go or RFID-blocking technology for added security. Overall, backpacks are a practical and stylish accessory that can be used for a wide range of activities, making them a popular choice for people of all ages.