Original: Native Command Queuing (NCQ) is a technology designed to increase performance of SATA hard disks under certain situations by allowing the individual hard disk to internally optimize the order in which received read and write commands are executed.
Simplified: Native Command Queuing (NCQ) is a technology designed to increase performance of SATA hard disks on computers. It can do this under certain situations by allowing the individual hard disk to internally optimize the order in which it executes the read and write requests it received.