What is static1.somedomain.com when you browse to a site?

Many a times it happens that when I browse to some site, the site brings some content from some other other domain eg. static1.somedomain.com

Example: When I browse Facebook it bring some of it's content from http://static.ak.fbcdn.net/. What is the actual purpose of this and why don't they put that content on the sam开发者_JAVA百科e domain instead of purchasing a new domain for nothing? Are there any specific advantages to this?

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It's a static subdomain. The purpose for doing this is that cookies are always sent to the main domain and not alongside of pictures and JavaScript(from the client side). So a client has to transmit less data.

The second thing is that a server which always delivers static contents has different key parameters like IO, memory, CPU as a dynamic node. If you separate servers by static/dynamic you can roll out different scaling strategies.

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Not sure if this is the right forum for your question but this SO blog answers all you queries