And these are just the tip of the iceberg. In general, if you need to put a computer system in place that
processes, shares, or otherwise manages data, you'll need a server.

The questions of how a server differs from a desktop and when a server is the right hardware solution are easy to answer. But the answers to the remaining questions -- how much server you need to buy, what kind of configuration you need, and of course, how much it will all cost you in the end -- are based entirely on what you plan to use the server for. One of the significant benefits of servers is that you can customize their configurations to meet your very specific needs, so you can concentrate your money in those areas where you need it most.
 
It probably won't surprise you to find out that a server typically costs more than a desktop, but then again, a server is designed to do more than a desktop. It might, however, surprise you to find out a solid entry-level server doesn't cost that much more than a high-end desktop, and may fit more comfortably into your technology budget than you might have imagined. Many file/print and Web servers (two of the most common uses for servers in small and medium businesses) come well equipped for a reasonable price.
 
The most important thing you can do to ensure that your server meets your needs and fits your budget is to devote a bit of time and energy to assessing those needs. Until you have a good understanding of exactly what you want to use your server for, you run the risk of not buying enough server power, or spending too much of your valuable budget on features you simply don't need. A little planning in the beginning can make for significant savings and proper equipment sizing in the end.

Server technology and benefits notwithstanding, you don't want to make technology purchases that won't benefit your bottom line, facilitate key business processes, or otherwise make your life easier. While there is no single litmus test that you can use to determine if you need a server, some general guidelines do apply.