How do big Websites like Youtube manage to have their data available all arround the globe?

Question

Now, even though this isn't a strictly programming related question, this is something I was wondering about for a while now.

Imagine, you upload a Video in the US and someone wants to watch it in Europe. How is it possible, that data uploaded on the other side of the planet is available at such fast speed. I am certain that there are servers everywhere, but how is the data synched between all of these?

Answer 1

I know Cloudfront can do this job http://aws.amazon.com/cloudfront/

Answer 2

Indeed, Superuser might be the better board for this question. Anyway:

Since the internet is .... very fast :D, I can watch a youtube video from a US server without any trouble. You can minimize the latency time by locating the users location and provide a datasource on a nearby server.

To do this, you just copy the video from fileserver USA to fileserver Luxenburg...thats the magic behind it.

EDIT: You may also want to read about latency http://www.o3bnetworks.com/media/40980/white%20paper_latency%20matters.pdf