Glossary of Terms

  • Simply put, a Byte represents a single character stored on a computer. This means a letter, number or typographic symbol takes 1 byte to store on the hard drive.
  • The CPU stands for Central Processing Unit, and can be thought of as the brain of your computer. CPUs are made by 2 major manufacturers, Intel and AMD. Your choice of CPU normally affects your choice of motherboard as well.
  • A Gigabyte is 1 024 Megabytes.
  • The GPUis more commonly know as the graphics card, but the acronym stands for Graphics Processing Unit. Modern graphics cards can be the single most expensive component in a desktop system, especially for the top end cards.
  • A Hard Drive is used for permanent storage of data on a computer. They come in different sizes, and modern hard drives typically start at around 500 GB in capacity, and can go up to approximately 14 TB for commercial equipment.
  • A Kilobyte is 1 024 bytes, or 2 to the 10th power. Many people approximate this by saying a kilobyte is 1 000 bytes.
  • A Megabyte is 1 024 Kilobytes, or 2 to the 20th power. Many people approximate this by saying a megabyte is 1 million bytes.
  • The Motherboard is the main electronic board - all other components are attached or plugged into the motherboard. Your choice of motherboard affects many other aspects of your PC specification, and is therefore something that you need to carefully consider. Among others, it will affect what CPU you can use (Intel and AMD CPUs are generally not compatible), how much RAM you can add, how many hard drives can be added, the types of hard drives that can be added and importantly, the graphics cards that can be added. For many users, even such things as how many USB ports are available, is an important consideration.
  • The OS or Operating System generally refers to Windows (latest version is 10), Linux or Mac OS. Windows has by far the largest market share. An OS in its most general sense, is software that allows a user to run other applications on a computing device. While it is possible for a software application to interface directly with hardware, the majority of applications are written for an OS, which allows them to take advantage of common libraries and not worry about specific hardware details.
  • The PSU is the Power Supply Unit. For PCs, it is a very important decision when selecting the PSU. Firstly, each PSU has a power rating - anything from around 450 W all the way up to 1 200 W. This is important because you need a PSU that is big enough to power all the devices and equipment that makes up your PC. This includes the motherboard, hard drive, CPU and especially the Graphics Processing Unit (GPU) which can consume a lot of power. On some PCs, people like to 'overclock' the CPU, which makes it run a lot hotter - this means that they need to also attach a liquid cooling unit to the CPU to ensure that it does not overheat, which can lead to other problems. All of these devices need power, and you don't want to find at a later stage that you can't add a component simply because you don't have a PSU with a high enough power rating.
    Secondly, PSUs also have a rating, which specifies the efficiency of the power supply. It is generally accepted that for PCs running for long periods of time, an 80 Plus Gold certified PSU offers the best value. The table below illustrates typical values.
  • 20% load50% load100% load
    80 PLUS80%80%80%
    80 PLUS Bronze82%85%82%
    80 PLUS Silver85%88%85%
    80 PLUS Gold87%90%87%
    80 PLUS Platinum90%92%89%
  • RAM stands for Random Access Memory, and is typically what people mean when they ask "how much memory does your computer have?" RAM is volatile memory, which means that when you switch off your machine, any information in RAM is lost.
  • SSD stands for Solid State Drive, very similar to flash drives that many people use to transfer data from one machine to another, via the USB port. A solid state drive is many times faster than a normal hard drive, but tends to be quite expensive, especially when you compare cost per GB or TB. Standard hard drives can be 5 times cheaper than SSDs, offering much greater storage capacities. The latest SSDs take advantage of an interface known as NVMe, or Non-Volatile Memory Express - these drives are 5 to 10 times faster than a standard SSD and can significantly improve the performance of a PC.
  • A Terabyte is 1 024 Gigabytes.