You would like your company to be generically associated with a concept.
For example, if you are in the business of selling step-ladders, you might want a site called "step-ladders.com" You would like a domain name to reflect your cool personality.
You would like to indulge in a bit of speculation/investment at a relatively low price. Everybody else has one, so why not get one too? Once a domain name has been established, "subdomains" can be created within the domain.
For example, the domain name for a large company could be "bigco.com" and within this domain, subdomains can be created for each of the company's regional offices. The structure for this is:
hostname.subdomain.second-level domain.top-level domain
For example, tiger.newyork.bigco.com
describes a single host computer named tiger, in the New York office of the Bigco Company. Not all domain names will have a hostname and subdomain. In addition, more than one subdomain can be assigned
