The majority of computers rely on a few simple concepts, the most basic of these being that of expansion. This is the idea that the computer will eventually become outdated, and can easily be updated through the use of expansion slots. For example, if your video becomes outdated, you can actually plug in a new video card and gain instant access to better graphics assuming your hardware can handle it. In addition to that you can upgrade the sound card, the network card, and other items that will get the computer ready for the next generation of software. A single board computer on the other hand cannot be upgraded, and it has a very specific purpose.
This is not to say that the single board computer is incomplete by any means. In fact, it runs perfectly fine, performing all of the functions expected of a functional computer. The single board computer is not typically designed for users, but rather for demonstration systems, or even educational systems. In addition to that they can be used as embedded computer controllers.
The term single board computer implies that the machine is entirely self contained, without relying on expansion cards. It will however rely upon optical drives, a power supply, and even cooling fans depending on what the machine will be doing. Because these boards do not call for expansion cards, you will find that they can fit in unusually slim cases. For reference you might think of these as blade servers used in large scale server racks. This is a great space saving technique, and expansion can be handled through backplane s if the need ever happens to present itself.
Another common use for single board computers would be that of home entertainment devices. For example you might find such boards in the new Blu-Ray players, along with DVRs provided by cable services. These single board machines can be upgraded remotely by the manufacturer, and by the users if the end user in question is willing to void the warranty.
Because these do not call for any expansion cards, they are a bit cheaper, and there therefore used quite commonly in slot machines and other casino machines that serve a single, repetitive purpose. Display machines and anything that serves a single purpose is a good candidate for single board computers. These computers are made possible by increasing the density of integrated circuits. That being the case, one board is capable of holding all of the necessary circuits required for full functionality. In the end you have a highly functional, cheap computer. So long as you do not need it to do anything extraordinary in the future, you will find that it serves you quite well.
From slot machines to displays you might place around your office, you will have a computer that stands the test of time, and gives you the flexibility you need. Because of the applications you will be using these computers for, you will find that the lack of upgradability is not a serious problem. For example, a slot machine will always have one and only function, and it is the same with any display computers you might be deploying. If you need to deploy any type of device that will perform the same action over a long period of time, then you should begin searching for the right single board to host your operation. They are easy to set up, and before you know it you will have the best business solution, and the cheapest computing solution. Your success is only a single board computer away.