The most popular of the portable media inputs for computers is the USB input. The Universal Serial Bus input is used to improve plug and play compatibility so that devices can be easily connected to a computer without having to restart the computer or install additional software. Flash drives are especially popular among USB inputs, but various other programs and hardware will use this. This bundles MP3 players that use USB connections to connect the player to the computer or portable video players that work in the simular way. Hardware for the computers have been using USB inputs too, including computer speakers, monitors and printers.