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What is a hostname versus a computer name versus a subdomain versus www? RRS feed

  • Question

  • I was searching to try and understand what is the “www” at the beginning of so many web addresses in the Internet I read in somewhere that “www” is called “hostname”.

    The world “hostname” made me go a step further in searching, I read so many threads and articles but I am still confused about that.

    So I decided to ask some related questions here to make it clear and I need solid and comprehensive answers please.

    1. hostname vs. computer name: Is the “hostname” the same as the computer name, if its true, suppose that my computer is a web server and my computer name is “Robin” so is it correct to conclude that a hypothetical web site would be something like: `Robin.websitename.com`?

    2. hostname” vs. subdomain: If “mail” in `mail.google.com` and “developers” in `developers.google.com` are called subdomains why is `en` in `en.wikipedia.org` called hostname? What is the difference between host name and subdomain?

    3.What is the relation between host name and fully qualified domain name (FQDN)?


    4. What is the “www” in URL of some web sites? As you know Google’s web address is `www.google.com` but we have many web sites without “www” for example: `superuser.com` and `en.wikipedia.org`. I read in this article that “www” is just a declarative thing not more and is not related to the concept of hostname. Do you verify that?



    • Edited by MR_sia Monday, March 9, 2015 10:49 AM
    Monday, March 9, 2015 10:45 AM

Answers

  • Hi,

    1. hostname vs. computer name.
    Computer name: open Control Panel – System, you will see Computer name. Notice the Full computer name(also called FQDN).
    Host: A computer or device on a network that has an assigned IP address (such as a workstation, a server, a Domain Controller, or a network-attached printer, etc.).
    Host name: A host name is typically the left-most portion of a domain name that identifies a specific named host on the network.

    Usually, for IIS web site, we may access the web site by DNS(http://ww.domain.com/), IP address(http://192.168.2.3/), or computer name(http://web1/, and this is mainly applied for internal clients to access the site). If client access the web site by name, related DNS entry is needed(such as A and CNAME record).

    2. hostname vs. subdomain.
    About subdomain, read the link below to know Domain Namespace:
    https://technet.microsoft.com/en-us/library/cc958962.aspx?f=255&MSPPError=-2147217396

    3.What is the relation between host name and fully qualified domain name (FQDN)?
    A Fully Qualified Domain Name (FQDN) uniquely identifies the host’s position within the DNS hierarchical tree by specifying a list of names separated by dots on the path ending in a trailing period.
    For example, FQDN(dc01.domain.com) = host name(dc01) + DNS suffix(domain.com)

    4. What is the “www” in URL of some web sites?
    Reference FZB’s reply.
     
    Best Regards,
    Eve Wang


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Wednesday, March 11, 2015 6:58 AM

All replies

  • many of those terms are ambigious, depending on in what context they are used. as you relate mostly to the web, you can take a look at http://en.wikipedia.org/wiki/Domain_Name_System for how domain names are put together.

    1. in your example, hostname would be the name in DNS referring to the address of the computer hosting the site. the computer name (NetBIOS name of the computer) could differ. for example the computer named "srv-web-01" could host multiple websites, each with their own hostname (www.domain1.com, www.domain2.com etc)

    2. the system is like hostname.(subdomain.)domain.topleveldomain. see http://en.wikipedia.org/wiki/Domain_Name_System#Domain_name_syntax

    3. host name is part of the full qualified domain name (http://en.wikipedia.org/wiki/Fully_qualified_domain_name ). if you just use hostname's, names like mail or www will not be unique, FQDN is unique. propably could compare it to street names, together with info in what city the street is, it should be unique

    4. see the section wildcard here https://www.ntchosting.com/encyclopedia/dns/default-dns/ . basicly, the request without the www is in the background forwarded to the hostname www

    Monday, March 9, 2015 12:02 PM
  • Thank you for your attempt but I need to someone  elaborate these concepts. I had seen the links that you mentioned but I need to someone explain these concepts in plain English.
    • Edited by MR_sia Monday, March 9, 2015 1:21 PM
    Monday, March 9, 2015 12:45 PM
  • Hi,

    1. hostname vs. computer name.
    Computer name: open Control Panel – System, you will see Computer name. Notice the Full computer name(also called FQDN).
    Host: A computer or device on a network that has an assigned IP address (such as a workstation, a server, a Domain Controller, or a network-attached printer, etc.).
    Host name: A host name is typically the left-most portion of a domain name that identifies a specific named host on the network.

    Usually, for IIS web site, we may access the web site by DNS(http://ww.domain.com/), IP address(http://192.168.2.3/), or computer name(http://web1/, and this is mainly applied for internal clients to access the site). If client access the web site by name, related DNS entry is needed(such as A and CNAME record).

    2. hostname vs. subdomain.
    About subdomain, read the link below to know Domain Namespace:
    https://technet.microsoft.com/en-us/library/cc958962.aspx?f=255&MSPPError=-2147217396

    3.What is the relation between host name and fully qualified domain name (FQDN)?
    A Fully Qualified Domain Name (FQDN) uniquely identifies the host’s position within the DNS hierarchical tree by specifying a list of names separated by dots on the path ending in a trailing period.
    For example, FQDN(dc01.domain.com) = host name(dc01) + DNS suffix(domain.com)

    4. What is the “www” in URL of some web sites?
    Reference FZB’s reply.
     
    Best Regards,
    Eve Wang


    Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Support, contact tnmff@microsoft.com.

    Wednesday, March 11, 2015 6:58 AM