A backpack is a versatile and practical bag designed to be carried on the back using two shoulder straps. It is commonly used by students, travelers, hikers, and professionals to carry books, clothes, laptops, or other essentials. Most backpacks have multiple compartments and pockets for better organization and easy access to items. Made from materials like nylon, polyester, or canvas, backpacks are designed for comfort and durability. Some advanced models also include padded backs, adjustable straps, and water-resistant features for added convenience.