How can things travel through the internet so fast?

How does data through the internet travel so quickly, instantly? How can an email get from the US to Spain just like that? Or anywhere around the globe for that matter. And does whatever you send really go to that place? Do emails go through satellites in space, and then back to Earth? Or does it go through cables embedded on the ocean floors? Also, Skype, how do they make video calls and how is one able to see and talk to someone that is on the other side of the world as if you are sitting next to him or her? How do video calls go through the internet? Do they travel through satellites in space, or cables across the oceans?