List of Parts of a Computer

A desktop computer (a PC) has various hardware parts that can be replaced, that is, bought, sold, and exchanged, generally with the intention of improving the PC's performance. For reference, I'll list here some of these parts.

Let's start with the basic parts that we can see that every computer has.

The keyboard is an input device used to type texts in a computer. Most of its keys represent letters, but there are also keys that represent spaces, numbers, symbols, diacritics, and that have special functions. Keyboards have different key layouts. The most common for English is QWERTY. Other layout examples are AZERTY and Dvorak.

The mouse is an input device used to point at objects on the screen and interact with them (through "clicks"). In reality, a mouse isn't necessary to use a computer, but the majority of programs will assume that you have one. Mouses come in various sizes. Most mouses have two buttons (left and right), and a scroll wheel in the middle that also works as a middle button, but there are also mouses with less and more buttons. Some mouses are symmetric and can be used by both right-handed and left-handed people, but there are also mouses with asymmetric designs made to be used with the right hand. If you are left-handed, it's important to pay attention on this before buying a mouse. In the past, mouses used to have a ball inside of them in the bottom to sense movement. Modern mouses have a laser instead. Be careful when looking at the bottom of the mouse while it's turned on.

The monitor screen is an output device where are displayed images from the computer. There are monitors in all sorts of physical sizes and digital resolutions. Although most are straight, there are also curved monitors. Some monitors can be rotated so their screens are taller than they are wider. It's possible to install multiple monitors in a single computer, displaying different programs in each one.

The computer case is a box typically black or beige where are placed the internal components of the computer. This box normally has a power button to turn the computer on and off, buttons to open the CD drives, and various holes (ports) where can be plugged cables such as USB. There are cases of all sorts and designs both internal and external. The case itself doesn't influence the performance of the PC, it's simply a base where are screwed the internal parts. However, more powerful computers will have a higher number of internal parts and these parts can be bigger in physical size, which means they may not fit inside a small PC case. When you purchase better internal parts for an upgrade, it's possible you'll have to buy a bigger case too to accommodate these new parts.

Next we'll see the parts that are inside the computer case and that normally we don't see.

The motherboard is where other internal parts of a computers are placed. Generally, the motherboard doesn't work with parts much older than itself, nor with parts much newer. Consequently, it's common to have to replace the motherboard when migrating from an old computer to a computer of newer generation. When buying a motherboard, it's important to pay attention first if it's compatible with the other parts that you own, e.g. if the PCI and SATA ports are in number and version compatible, if the capacity and type of memory is compatible, and, mainly, if the CPU socket is compatible. Besides that, motherboards come in various sizes, and, naturally, large sizes simply won't fit in small PC cases. There are situations where it's not possible to install a large graphics card directly in a small motherboard due to the layout of the slots, e.g. the memories occupy the same physical space that the graphics card would need.

A power supply unit, or PSU, is responsible to supply the electricity to the various internal components of a computer. A more powerful computer requires more electricity and with that it's necessary to buy a power supply of higher potency.

The CPU (central processing unit) contains the main processors of a computer, called CPU cores. Large part of the use and performance of a PC depends on its CPU. On other hand, modern CPUs are extremely capable, and with that performance problems usually originate from other components.

The RAM (random access) memory is where are stored temporarily data that would be processed by the CPU. This data is lost when the computer is turned off. The purpose of the RAM is simply to hold the data that is being processed at the moment. Data that should be saved permanently, that should not be lost when the computer loses energy, or that simply don't fit inside the RAM installed in the computer, are sento permanente storage media such as hard disks. These media are much slower than the RAM, but data inside them aren't lost when the power goes off. Every motherboard has a maximum limit of RAM tat can be installed, and generally there's no reason to not install the maximum amount possible, except for the cost.

The graphics card, or GPU, is a component specialized in the processing of visual computations. Every computer that displays something in a screen has a graphical circuit. Some computers use a graphics circuit integrated in the CPU, which is usually very basic, but works. Powerful computers use a separate graphics card, which can be the component that uses the most amount of electricity in the computer, specially given the ultra-realistic games of nowadays. It's common to replace the power supply for a better on when buying your first graphics card.

A cooler is a component responsible for cooling internal parts of a computer that can become very hot, specially the CPU, GPU, and power supply. If they are not cooled, their temperatures can reach 100 Celsius degrees, which would damage the components. There are various types of coolers. The most simple one is a small fan that throws hot air away from the component. With time, these fans can get full of dust, which hinders their ability to cool the components and decrease their lifetime. There are also coolers that use water instead of air to cool the components, called water coolers.

The hard disk, or HD, is a disk where are permanently stored your files and computer programs. More specifically, the part that you buy is the hard disk drive (HDD), which is the device that reads and writes a disk that is inside of it. This drive is connected to the motherboard through a SATA cable and is connected to the power supply as well. Considering this, it can get complicated to have a large number of drives inside a single PC.

The SSD (solid state drive) has the same function as the hard disk: store files and computer programs permanently. The difference is that the SSD uses a different technology, which costs more to store the same amount of data, but that on the other hand is capable of reading and writing data with higher speed. The recommendation is to have a SSD where are written files of the operating system that are processed all the time, besides other programs and games, and a HDD where are stored personal files like images, videos, music, documentos, and projects. The faster SSDs are so fast that their reading speed is higher than the amount of data that can go through a SATA cable at once. Given that, it's necessary to use a different technology, the NVMe, to make sure of their maximum speed. In this case, the SSD is connected through a PCIe slot instead of SATA.

Besides HDD and SSD, a computer may read and write data to inside of a CD, DVD, BD (blu-ray disc), floppy disk, etc. For this, it's necessary to have the respective drive: CD drive, DVD drive, BD drive, and floppy drive. These drives are connected through SATA, just like the HDD.