Building a network server means much more than assembling hardware. This article explains critical steps in putting any machine onto the Internet for public access. This article focuses on the requirements for putting a server on the public Internet. Most functions also apply to a local intranet, but you would substitute "network administrator" for ISP in these instructions.
There are a few different ways to get your presence into the public eye on the Internet. This section outlines how you might take a machine you already have and adapt it for use on the Internet. Step one is ensuring the system has Internet software and more specifically, is using the Transmission Control Protocol / Internet Protocol (TCP/IP). As it's name implies, this protocol underlies all the client and server functions performed on the Internet. If the computer you will be using is already communicating with the Internet, it's likely already got the protocol installed.
An Internet Service Provider (or ISP) represents the way your system will get onto the Internet. When discussing your needs with your ISP, be sure to notify her of your intent to run an Internet server. There can be a world of difference between just surfing the Internet through your ISP and hosting an Internet server through your ISP. Beyond any planning she may need to do in order to accommodate your server traffic volumes, you will need to request a "static IP address."
An IP address is a bit like a telephone number. It's unique on the net, and it's used to connect two parties for a conversation. Like making a telephone call, when you are the one starting the conversation, it does not matter much which phone you use because you're the one starting the conversation. In order for you to be reached by someone else, however, your unique number has be fixed and published--or at least known in advance. Most Internet clients are given a temporary number by their ISP because the work most clients do on the Internet is the type that dials out--that starts the conversations with other systems. To be an effective Internet server, your system cannot have just any number, it must have the same number day after day or client computers would not be able to guess what number to dial. This is your needed static IP address.
Though it is technically possible to stop at the static IP address, virtually everyone goes the extra step to establish a friendly name for his IP address. It's a good bit easier to remember "google.com" than it is to remember 22.214.171.124. The Internet community understood this years ago and built a massive, global translator system called the Domain Name System (DNS). Though it's a good bit more complicated, it's useful to think of DNS as a giant phone book for the Internet. When a web browser wants to look up the number for www.google.com, it asks DNS for the number. DNS answers the question, and the browser uses the Internet number for www.google.com.
In order for your Internet server to be found using a friendly name, your server must get an hostname entry in your domain's DNS database. Hostname entries associate the IP address of the machine with the domain name people will look up using DNS (e.g. www.sun.com). Whatever agency helped you secure your domain name will likely have instructions for updating the DNS entries for your domain name. Follow those instructions to establish the hostname for your server.
Now it's time to load your system with software that provides some type of service to the Internet community. Common services are web services and FTP services---both of which can be enabled on most systems without additional charge. Microsoft ships Internet Information Server (IIS) with its operating systems. Apple also ships with both web and FTP servers, as do Solaris (by Sun Microsystems) and most popular distributions of Linux. Apache's web server software (the most common web server in production on the Internet) is freely available for most popular operating systems, at http://apache.org.