HBA(Host Bus Adapter)
A card that adds many drive ports, commonly flashed to pass disks straight through to ZFS.
For a ZFS NAS you want an HBA in 'IT mode' rather than a hardware RAID card, so ZFS has direct access to each disk and its SMART data.
Related articles
ZFS
An advanced filesystem and volume manager offering data integrity, snapshots, compression and software RAID.
PCIe(Peripheral Component Interconnect Express)
The high-speed expansion bus that connects GPUs, NVMe drives and network cards to the CPU.
JBOD(Just a Bunch of Disks)
A group of drives exposed individually, without hardware RAID combining them.