thumb |upright=1.3 |Fibre Channel host bus adapter (a [[64-bit PCI-X card)]]
thumb |upright=1.3 |SCSI host adapter (a [[16-bit ISA card)]]
In computer hardware a host controller, host adapter or host bus adapter (HBA) connects a computer system bus which acts as the host system to other network and storage devices. The terms are primarily used to refer to devices for connecting SCSI, SAS, NVMe, Fibre Channel and SATA devices. Devices for connecting to FireWire, USB and other devices may also be called host controllers or host adapters.
Host adapters can be integrated in the motherboard or be on a separate expansion card.
The term network interface controller (NIC) is more often used for devices connecting to computer networks, while the term converged network adapter can be applied when protocols such as iSCSI or Fibre Channel over Ethernet allow storage and network functionality over the same physical connection.
SCSI
A connects a host system and a peripheral SCSI device or storage system. These adapters manage service and task communication between the host and target. Other manufacturers include Agilent, ATTO, and Brocade.
HBA is also known to be interpreted as High Bandwidth Adapter in cases of Fibre Channel controllers.
InfiniBand
The term (HCA) is usually used to describe InfiniBand interface cards.