Thunderbolt is exciting for its bandwidth and the versatility of how it carries data. The latter allows a port to morph into another kind, as with Apple's FireWire and Ethernet adaptors. That same flexibility allows the Matrox DS1 to add a variety of extra ports in one box.
It's designed for MacBooks, so the Thunderbolt port is at the front, with rear cables to downstream devices. It works best with short Thunderbolt cables, but it's awkward with desktop Macs and small desks.
Sitting alongside it is a USB3 port, which 2011 Macs lack. Its speed is limited to 2.5Gbps, not the 5Gbps of which the standard is capable. (But since lots of devices can't take advantage of that peak speed anyway, it's currently something of a moot point.)
More demanding devices might indicate only that USB3 is required, leaving you in the dark about whether they'll perform optimally with the DS1.
On the back are two USB2 ports, analogue audio input and output minijacks, Gigabit Ethernet, and, depending on the version, a singlelink DVI or an HDMI port. Matrox says FireWire is omitted because it's niche nowadays.
Even without it, the DS1 is a desirable yet costly way to make light work of reconnecting multiple devices.