What Are the Four Main Components of a General Purpose Computer?

As a business owner, you will most probably need at least one general purpose computer for your administrative work. Internet research will tell you that any basic computer consists of an arithmetic logic unit (ALU), a control unit, main memory and your input-output devices. However, these are not commonly used terms at the computer shop, and will not get you very far if you are trying to buy a general purpose computer. Besides the monitor, keyboard and mouse, which are effectively output devices, you will require four basic hardware components in the case of your PC: the motherboard, central processing unit, hard disk drive and power supply.

Choosing the right motherboard is very important, as all of the other components slot into this piece of hardware, so you have to ensure that everything is compatible with each other. For a general purpose computer, you won't need a top-of-the-line motherboard, but if you want to avoid upgrading too soon again it is best to go for a model that can accommodate all the latest technology. This will prevent you from having to replace the motherboard if, for instance, you decide to upgrade the CPU. For a general purpose computer, an integrated motherboard that has the graphics card, sound card and network card on-board should be the cheapest option, so you won't need to buy those cards separately. Also be sure to ask for compatible RAM when you purchase a motherboard. The amount of RAM influences your system performance, so what you choose will depend on how fast you require the computer to be.

As it is the "brain" of your PC, the CPU is one of its most important components. The processor determines what your computer is capable of and how fast it processes tasks. Modern-day CPUs all have multiple cores, which means it can process different tasks simultaneously. The more cores, the faster the CPU will be -- but it will also be more expensive. For a general purpose computer, a dual core should be sufficient unless you are planning to do very intensive video and photo editing.

Every computer needs a storage component, and for a general purpose computer a hard disk drive should be sufficient. Other options include a solid state drive or a hybrid between a SSD and a regular hard disk drive. These options are more expensive than a normal hard drive, although both are a bit faster at finding data as they make use of flash memory. As of 2013, hard disk drives can store capacities of up to four terabytes, but a general purpose computer doesn't need that much unless you work with large video and image files that take up a lot of space.

The power supply is the device that converts power from your outlet to the other components, so each component gets what it needs. Each piece of hardware in the computer has other power requirements, and the power supply has to provide that. The more components in your computer, the more power they need to draw, and the higher the required capacity of your power supply. For a general purpose computer, a 350-Watt power supply should be sufficient. However, don't skimp on your power supply and buy the cheapest out there unless your area has a very stable power connection. High-end power supplies have extra built-in safety features to protect the system from power surges.