Laptops are personal computers designed for mobile use that integrate components like a display, keyboard, touchpad, and speakers into a single unit. They can be powered by an AC adapter or battery, allowing them to be used away from an outlet. Laptops come in various forms like standard notebooks, subnotebooks which emphasize portability through small size and weight, and convertible laptops which have displays that can rotate and lie flat. Laptops allow users internet access through WiFi and portability to work anywhere. Their compact size and ability to run on battery power has made them popular replacements for desktop computers.