NUC, which stands for Next Unit of Computing, is a small form factor computer kit manufactured by Intel. Their motherboards measure four inches by four inches. They come with a plastic case and a CPU fan, and an external PSU — the case has no room for an internal power supply. They also come with VESA mounting brackets, so the NUC can be mounted to the rear of an LCD monitor.
There have been three generations of NUC released since 2011, based on Sandy Bridge, Ivy Bridge, and Haswell CPUs respectively. The CPU is soldered to the motherboard, so it is not upgradable. They come with onboard gigabit Ethernet and can utilize Wi-Fi via a PCI-e slot or one of the USB 2.0 ports. Some models come equipped with a USB 3.0 port, as well.
Because of the small form factor, there is no room for a discrete graphics card. The graphics are powered by an onboard NVIDIA chip, and video output is provided by Mini HDMI or Mini Display Port, depending on the model. All NUCs support SSD as their storage device. Some NUCs also come with a slightly taller case, providing a connection and enough room to install a 2.5-inch SATA drive.