Why domain name may not work?
I have been a bit busy and I had not checked on this site for a while. BIG mistake because my domain had expired meanwhile. I hadn’t noticed that because A) I don’t visit my own site all that often and B) my registrar had my old email address that wasn’t functional anymore (tip of the day: never use work/school address anywhere as it will probably change at some point). All messages that the registrar had sent me went into cyberspace where no-one read them…
Lummox me had made very simple but quite common mistake and forgot to take care of my site. I’m really sorry for that.
Other reason for unrespondable domain might be that the IP-address has been changed but the owner hasn’t changed it on the domain’s control panel. There are huge amount of different reasons why the IP-address changes: it may just happen (IP-addresses are leased, so some day you kind of a like have to get another one), maybe the page is moved somewhere else or network administrator has made some changes…
For some reason people seem to have difficulties on understanding this IP-thingy. So, let’s put it like this: you have a mobile phone and your friend also has one. For some reason you decide to change them between each other without changing SIM-cards or anything that sort of matter. Of course then someone calling to your friend’s phone is now calling to you and vice versa.
IP works in same manner: even if your domain name is unchangeable, its address may not be the same. In the phone case the phones and people didn’t change but which number was with which person did.
Domains are found based on their IP-address (which will change over time) because name servers (=address-/phonebooks) direct traffic to sites. Whenever an Internet-user tries to access into a site, their computer will make a query to name server that where the domain is located and where they should go. And if the name server does know, it will give the computer the IP-address where it needs to send its next queries. (And if it doesn’t know, it will point out another name server that might know better).
Just like your old friend might be looking for you, and he checks from a phonebook where you live. If the phonebook is old or no-one has gave it proper up-to-date information about your location, you friend will be looking from a wrong place and can’t find you.
Another thing: it won’t work that you email someone a bath where some file should be found it the address is “C:\\My Computer\My very own files\...”. They are located on YOUR computer and no-one (hopefully) has an access into it.