Some laptops or tablets connect via a USB port. Other manufacturers have even created proprietary ports that allow tighter integration and a cleaner form factor. Regardless of how you get connected, laptop and tablet users have enjoyed docking stations for years.
Using a laptop on the go can feel limiting. Trackpads are usable, but not ideal. Some smaller laptops don’t even have full size keyboards, and hardly any of them have a number pad. Having a docking station at your desk takes all that away. As soon as you connect, you have access to a mouse and keyboard, additional monitors, and who knows how many other devices you might have plugged in.
Owning a laptop or tablet with a corresponding docking station yields the best of both worlds. You have a workstation that feels “full size” but can easily take your work on the go. That’s the same thing Nintendo tried to do with the Switch. You have a full-featured console experience at home that you can take with you when you leave the house.