Registration of a domain name buys you an Internet address that no-one else in the world can use.
The registration is for a set number of years and you have the first rights to renew the name at the end of this period.
What some people do not appreciate is that registration is only the lease of a unique Internet address for your exclusive use. It provides you with the place where you receive your emails but Email messages arriving via your domain name need to be forwarded to a place from where you can then access them. This is typically your current internet provider or a facility provided by a business, professional association, charity, educational institution, etc.
At the end of the registration period, you have to renew the registration or you will lose the right to continue using the domain name. In order that we can remind you when re-registration is due it is essential you keep us up to date with changes in your Email and postal addresses. If you are likely to be changing your postal address frequently we would encourage you to provide us with one that is less likely to change, perhaps a head office or family home.