It includes a dual core i5-6260U, Intel Gigabit LAN port, Intel 8260 Dual-Band WiFi 802.11ac, 1x HDMI 1.4b port, 1x DisplayPort 1.2, SD card slot, place for one m.2 SSD and one 2.5" HDD/SSD... and of course, an external power supply. This unit is considered barebones, which means you'll have to add RAM, storage and OS, but everything else is included.
For those who purchase a unit, I recommend checking the BIOS version. It should be at least v42, as prior versions may have caused what is known as WHEA Errors. If not, after updating to the latest BIOS version, you should be good to go.
Another note - all USB ports are USB3.0. Installation of Windows 7 with SP1 is going to be a bit of a problem unless you create a media which includes the necessary USB3.0 drivers beforehand (often called slipstreaming). More recent versions of Windows - 8, 8.1 and 10, should install just fine as they already include USB3.0 drivers.
More info directly from Intel here.
BTW, I highly recommend adding a wireless keyboard+mouse set. The Logitech K400 wireless keyboard with built-in touchpad is what most people buy for a good living-room experience. It usually costs about $30 and is well worth it.