Once we have a name, how do we use it to connect to another machine? First we need to understand the client-server model of computing.
Let's start with an example from the real world. Most libraries have a reference desk you can call to get answers to questions. Let's say that the library has a main number, 555-6251 and the reference desk has an extension, say 67. So the reference desk phone number is often written as 555-6251 x67. In this example, the reference librarian is a server of information and you are the client. The client contacts the server at a well known address, the phone number and extension, and you communicate requests to the server using a standard protocol. In this case, the protocol is pretty informal. The key thing is that you and the librarian have at least one language in common.
In general, a client-server model has a client, with somewhat limited resources, communicate requests for services to a server, with much greater resources. The client and server could be programs running on the same or different computers. The terms are also used to refer to the computers running the software. So your home computer is a client and the computer running the web site you are talking to is the server. But also, the browser on your computer is the client and the program supplying web pages from the remote computer is known as the web server. So, to make sure that people are confused, the web server is usually running on a server.
Now let's see how this works on the web. In this case, the client is your web browser. The phone number of the library is the equivalent of the IP address or the internet name. We use the IP address to contact the computer we need. On that computer there may be several services provided by that computer. Just like the library has a reference librarian, a childrens librarian and so on. In the library example, we use a different extension for each service.