AHCI, or Advanced Host Controller Interface, is a technical standard that defines the operation of Serial ATA (SATA) storage devices. It allows for features like native command queuing, which improves the performance of hard drives and solid-state drives by optimizing the order in which read and write commands are executed. AHCI is commonly used in modern computer systems to enhance the efficiency of data transfer between the operating system and storage devices. By enabling hot swapping, it allows users to connect and disconnect drives without shutting down the computer, making it a convenient choice for both personal and professional use.