•  DNS (Domain Name System)

    All domain names have services associated with them, e.g. email, websites.
    Greatly simplified, DNS points users of these services to the correct locations on the internet.
    If I send an email to bob@eKit.co.uk, then an email server will use the domain name server to determine where to send that message to eKit.co.uk
    If I type bbc.co.uk into a web browser, it will use a Domain Name Server to find out where to request the bbc home page from.
Read the 'DNS' on Wikipedia