A computer is made up of many components that must work together simultaneously to power the machine. Computer hardware varies in speed, performance and features and is usually aimed toward a specific type of user such as those who simply want to browse the web or more run more intensive applications. Having a basic understanding of standard computer components can be help when making buying decisions.
Computer Case
Computer cases hold all internal hardware components. Cases come in various sizes and colors. The size of your case will dictate which motherboard options you have. ATX (full size) cases support both ATX and micro-ATX motherboards. Micro-ATX cases are limited to micro-ATX motherboards. How many internal hard drives and disk drives you can install is also limited to the amount of hard drive and disk drive bays inside the case.
Motherboard
The motherboard is essentially the hub of the computer; it houses all of the chips and cards that power the machine. Because motherboards are designed to work for a specific kind of hardware, knowing what type of motherboard you're using and what is compatible with the motherboard is vital when building a new computer or making upgrade decisions.
Graphics Card
The graphics card, also referred to as the video card, renders the images displayed on your computer monitor. While most motherboards come with integrated video, graphics cards are faster and offer more features compatible with modern 3-D technology and disk-based technology such as Blu-ray. Although many factors are involved, interruptions in video playback and slowdown in 3-D applications is usually the result of integrated video that cannot keep up.
Hard Drive
The hard drive stores all content you save to your computer, along with the operating system. Hard drives come in internal or external variants, with external drives usually costing more because the setup is easier. Although hard drives vary in speed (measured by revolutions per minute or RPM), even the slowest drives are suitable for most applications.
Mouse & Keyboard
Probably the most recognizable peripherals, the mouse and keyboard are essential to any desktop computer. There are various keyboard designs and sizes available to suit office, gaming or web browsing use. The same is true for the mouse, with some having additional side buttons or extra buttons on the scroll wheel. Wireless mouse and keyboards are becoming more common as they have become more reliable as the technology has improved, resulting in increased battery life and fewer disconnections.