Possible Duplicate:
What does wwws mean?
Today I got one link from my friend that starts with www2.zzzzzzzz.co something like that
what is difference between www1, www2 and www3 in url
2 Answers
Web farms and load balancing
Names like www1, www2, www3 are often used for members of a load-balancing farm of web-servers for popular web-sites where the workload is too much for a single server or where multiple servers are used to proivide continuity of service in the event of failure of a single server.
An example of how it works
A front-end server at initially receives the requests and redirects the browser to an available server in the farm, it does so by returning a HTTP redirect response to the browser, the browser then retries it's request using the redirected URL provided.
It's just a name
It may just be that some parts of a large website are handled by different servers and rather than naming the servers shop.example.com shareholder.example.com jobs.example.com they name them www1.example.com www2.example.com etc.
They're just sub-domains. Once upon a time sub-domains used to give a clue to the protocol used (e.g. ftp, gopher, smtp etc.) but today sub-domains are (mainly) just used to route traffic to a specific IP address.
