A domain name is your name on the internet. for example marcallabs.com is my domain name. It is mine and only I can use it. I have registered it and that gives me the right to use that name far as long as I continue to pay for the registration of the name. For an annual cost any domain name that is not already registered can be yours. Remember however that if you don not pay to renew the registration then you will lose the right to that domain name.
Every domain name has associated with it, contact details of the person or company that registered the name. When the domain name is due for the registration to be renewed an email will be sent to the contact details informing them that the domain registration needs to be renewed. If this contact information is not correct then the emails will not be received and the owner cannot make the decision to re-register or let the registration go. In this situation the registration is NOT renewed and the name will be let go.
When you own a domain name registration it is very important to inform your registrar of any email address changes.
This is where I come in. I will deal with all aspects of the domain name registration and will contact you when the domain is due for renewal and if you should change contact details I will make sure these are updated on the registration.