All of the docks require a power adapter.
Some of the docks are quite similar in design while others are vastly different. In this roundup, I tested eight docks that all use Thunderbolt 2. When you return to your desk, all you have to do is connect one cable. When you want to take your laptop, you only need to unplug a single cable. But essentially, the basic functionality of the docks is the same as before: You plug in your display, hard drives, printer, ethernet, headphones, USB devices, and whatever else into the dock, then you connect the dock to your laptop via a single Thunderbolt 2 connection. The market has also grown a little, with a few more offerings to consider. The major change since I last did a roundup of Thunderbolt docks is that the latest docks use Thunderbolt 2, which makes them aligned with Apple’s Thunderbolt 2 implementation in its MacBook Pro and MacBook Air.
