Atlas Obscura:

When you travel internationally, power outlets provide a pretty good reminder that you’re not in Kansas anymore.

Outlets vary wildly depending on the part of the world, both in the shape of their sockets and the voltage with which they’re compatible. For those who travel across multiple regions, it can be frustrating. And it’s probably too late to solve this problem, because of decisions made more than a century ago.

If you don’t travel internationally, you won’t know the aggravation of the world’s power outlets. Here is an interesting video about the British outlets and why they may be the best design.