What is the difference between the top-level and the second- level domain names?
The top-level domain and the second level domain work together to form the Internet address. The second level domain usually indicates the name of the organization that the address belongs to (e.g. Microsoft), or the type of web site it is (e.g. .com). When the two are tied together, the address is formed: “microsoft.com”. Any additions to this address would be simple and straightforward and are performed by Microsoft. For example, Microsoft has the sites www.microsoft.com and search.microsoft.com.