An EFI component that can consume a protocol in the handle database.

A term used by some of the EFI Driver Model-related services in the EFI 1.10 Specification to represent an image handle, a driver handle, or a driver image handle.

A term used collectively to describe the Block I/O Protocol, Disk I/O Protocol, Simple File System Protocol, and Load File Protocol.

Managed by a bus driver or a hybrid driver that produces child handles. The term bus does not necessarily match the hardware topology, but in this book is used from the software perspective, and the production of the software construct which is called a child handle is the only distinction between a controller handle and a bus controller handle.

Nearly identical to a device driver except that it creates child handles. The main objectives of the bus driver are to initialize the bus controller, to determine how many children to create, to allocate resources and create a child handle for one or more child controllers, to install an I/O protocol on the child handle that abstracts the I/O operations that the controller supports (such as the PCI I/O Protocol or the USB I/O Protocol), if the child handle represents a physical device, to then install a Device Path Protocol, and to load drivers from option ROMs if present. (To date, the PCI bus driver is the only bus driver that loads from option ROMs.)