Cont..

Some business owners confuse their web host with their internet service provider and further confuse both with the domain registrar. Since many ISP's offer web space, or hosting, and also provide domain registration through their initial signup package, it's not easy to separate the three distinctly different entities. You needn't host with your internet service provider and they're (almost) never your domain registrar. Keep them separate and completely apart in your mind.
Internet service provider. (AT&T, Verizon, SBC Global.)
Web hosting provider. (Pair Networks, Verio web hosts.)
Domain Registrar. (GoDaddy, Register.com Yahoo Domains.)
When a client recently moved her hosting, she asked me how to make that happen and had no idea how important the details were. We first established a new hosting account, then determined new domain name servers, uploaded her web files. we made sure that account was live with the new web host, then contacted the domain REGISTRAR to change to the new domain servers in a domain management console.

This same client had nearly told her old web host to close her account before we found out that the registrar had her old, previous email address as "Administrative contact" email for her domain name. It took two days to straighten that out and make corrections. Her site would have been down for two days if she had shut down her old hosting account as she had planned before speaking with me. She had a new hosting account set up, but failed to realize the importance of the registrar change to DNS server records in the moving scenario.

We then notified the previous host of the change, only AFTER the domain was resolving to the new host so that when the site was turned off at the old host, it was already working at the new host.

Don't be caught by surprise! You can protect your domain name by registering it for the maximum time of ten years and extend it every year to that final, tenth year, rather than waiting for it to near expiration. This will prevent you losing control of the name, but shouldn't mean you can forget your registrar login details or renewal date. How likely is it that you will move, or at least change internet service providers within that ten years? Be sure to keep your registrar apprised of new email, street address, phone numbers at all times! Especially that all important Administrative contact email. "WHOIS" your domain registrar? Do you have domain name management console login details? Have you extended your registration to ten years? Your business is worth careful domain name management.