Central Processing Unit (CPU)
The central processing unit (CPU) is essential to a computers ability to process information. The CPU performs the instructions of a computer program with arithmetic, logical, control and input/output operations. The speed of a CPU is typically measured in gigahertz (GHz.) A CPU with a clock speed of 2.0 GHz can process 2 billion instructions each second and one with the clock speed of 3.0 GHz can process 3 billion instructions each second.
Motherboard
The motherboard or “mobo” for short is considered the “mother” of all components attached to it. By means of printed circuits on the board, it holds and allows communication to many of the necessary electrical components such as the drive, processor, and video card.
Random Access Memory (RAM)
Random-access memory (RAM) refers to the memory that the microprocessor can read from and write to. RAM is much faster than hard disks or other memory which are limited by mechanical operations.
Hard Disc Drive (HDD)
The hard-disk drive (HDD) or “hard drive” is where files and programs are stored on a computer. HDD utilizes a spinning magnetic disk and magnetic heads on an arm called an actuator (much like a record player) to read from and write data to its surface. Hard drives are the most common option for data storage.
Solid State Drive (SSD)
Solid-state drives (SSD) are different than traditional hard-disk drives. Because SSD utilizes integrated circuits, its ability to read and write is not slowed by the physical limitations inherent in a hard-disk drive. SSDs degrade over time and are not suited for archival storage. Solid-state hybrid drives combine the features of both drives to maximize performance and reliability.
Graphics Processing Unit (GPU)
The graphics processing unit (GPU) also know as a video card is responsible for outputting images on a display such as a computer monitor. A faster video card will allow a computer to display higher resolutions and frame rates. Gamers and those who work with digital imagery such as video editing and 3D modeling tend to spend a sizable portion of their budget on a GPU.
Optical Drive
Optical drives include CD, DVD, and Blue-ray which use laser light or electromagnetic waves to read from or write to optical disks. Optical drives are becoming increasingly uncommon in new computers. Most of the tasks performed by optical drives can be done more conveniently with a USB flash drive or an internet connection.
Case
The case is the outer shell of a computer. A modern computer case looks sleek with high-quality materials that can improve noise reduction or fit a visual aesthetic. Cases also have features for managing wires and dust control. When selecting a case keep in mind front ports, size, sound deadening, and clearance issues.
Power Supply (PSU)
The power supply provides electricity to a computer. When selecting a power supply the best practice is to calculate the total watts of every component and add headroom. If a power supply is operating at full capacity it will use unnecessary electricity and create excessive heat and noise. A power supply that is 30%-50% more power than required is recommended.
Air Cooling
Air cooling is the most common cooling system found in computers. Modern computer fans and large heat sinks perform very well together. Air cooling can be quieter and less expensive than a water cooling system that delivers a similar performance.
Water Cooling
Water cooling exchanges heat by circulating water over hot computer components such as the CPU and GPU. The heat is usually exhausted out of the case using a radiator and a fan. Typically the best water cooling design is a full custom loop.