how do you get a domain that starts www2 (or similar)

[Solicitors Mortgages]

I have seen domains starting www3. or ww2. how exactly do you get these?
:confused:

thanks...

[tflight]

Sites that need additional servers to handle their web traffic setup additional servers to handle the load. Often they name them like that. The "how" is either a separate server or separate hosting account and using DNS ("A" records, round robin, etc) to point each subdomain to a different server.