Introduction
The basic parts of a desktop computer are
the computer case, monitor, keyboard, mouse,
and power cord. Each part plays an important role whenever you use a computer.
Watch the video below to learn about the
basic parts of a computer.
Looking for the old version of this video?
You can still view it here.
Parts Of A Computer And Their Functions (All
Components)
Going
over the basic parts of a computer and their functions will help you understand
all the vital components that make up a computer.
1. The computer case or system unit
This
is the component that holds all of the parts to make up the computer system.
It
is usually designed in such a manner to make fitting a motherboard, wiring, and
drives as easy as possible. Some are designed so well that it is easy to make
everything look tidy and presentable.
Cases
come in all different sizes and shapes to accommodate various types of
computer components and satisfy the consumer’s needs.
Design
elements can vary from plain to highly elaborate. You can get a plain grey desktop
case or one with colored lighting everywhere to make it look spectacular.
Computer
cases rely on computer fans inside them to create proper airflow to keep all
the internals cool and working reliably.
A
computer case, like most things, varies in quality. You can get them made from
cheap metals or good quality materials that provide you with a sturdy design.
List of computer case sizes (known as form factor):
- Very small form factor: Supports Mini ITX
motherboards
- Small form factor: Supports micro ATX motherboards.
- Standard form factor: Supports standard ATX
motherboards.
- Larger form factors: Supports ATX and XL-ATX
motherboards.
2. Motherboard
The
motherboard is the main board that is screwed directly inside the computer
case. All other cards and everything else plugs directly into the motherboard,
hence its name.
The
CPU, RAM, drives, power supply, and more are connected to it.
Its
function involves integrating all the physical components to communicate and
operate together.
A
good motherboard offers a wide amount of connectivity options. It also has the
least amount of bottlenecks possible.
This
allows all the components to operate efficiently and to fulfill their maximum
potential as they were designed to do.
Obviously,
as the physical size is reduced, it begins to limit connectivity options and
functionality.
Motherboards
come in the following sizes:
|
Motherboard |
Dimensions |
|
Pico-ITX |
3.9 inch x 2.9 inch | 100mm x 72mm |
|
Nano-ITX |
4.7 inch x 4.7 inch | 120mm x 120mm |
|
Mini-ITX |
6.7 inch x 6.7 inch | 170mm x 170mm |
|
Micro-ATX |
9.6 inch x 9.6 inch | 244mm x
244mm |
|
Standard-ATX |
12 inch x 9.6 inch |
305mm x 244mm |
|
XL-ATX |
EVGA: 13.5 inch x 10.3 inch | 343mm
x 262mm |
3. Central Processing Unit (CPU)
The
CPU or central processing unit is basically like the brain of computer systems.
It processes all the information on a computational level.
It
takes all the processes from the RAM and processes them to perform the tasks
required by the computer system.
The
central processing unit is usually seated in a socket that utilizes a lever or
a latch with a hinged plate with a cut-out in the center to secure the CPU onto
the motherboard.
It
has many copper pads underneath it for the socket contacts to push up against
them to make electrical contact.
There
are other ways CPUs can be attached to the motherboard.
Here
are some common examples:
- ZIF (Zero Insertion Force): Although this is a more
desirable socket, they are mostly found on older computer
motherboards. A lever-operated mechanism to clamp the pins of the
processor.
- PGA (Pin Grid Array): It is also a ZIF socket but
has a different pin pitch and contains a different pin count.
- LGA (Land Grid Array): More commonly found on
motherboards today. A levered hinged plate with a center cut-out clamps
down on the processor.
- BGA (Ball Grid Array): The CPU is soldered directly
onto the motherboard. This makes it a non-user-swappable component. It is
susceptible to bad connectivity.
A
processor generates a decent amount of heat, especially when it is working
under high loads.
It
will run even hotter when it is set to a higher clock speed to make it run
faster. This is called overclocking.
This
is why a heatsink and fan assembly are required to draw the heat away from the
central processing unit and distribute it to thin sheets or fins of metal for
the fan to cool down.
There
are so many different types of computer processors. The top manufacturers of
processors are Intel, AMD, and NVidia.
4. Random Access Memory (RAM)
RAM is
a data storage device that can provide fast read and write access. RAM is
volatile memory, meaning it loses all the stored data when power is lost.
The
RAM keeps data ready for the CPU to process. The RAM speed is a big contributor
to the overall speed of a computer system.
It
plugs directly into a long slot that has contacts on either side of the slot.
It,
too, has a clock speed, just like a processor. So, it can also be overclocked
to deliver increased performance beyond the intended specification.
Certain
RAM modules are sold with a heat spreader. It helps dissipate the heat from the
individual memory ICs, keeping them cooler.
RAM
has evolved like any other component. RAM used on the motherboard often uses
DDR (Double Data Rate) SDRAM (Synchronous Dynamic Random Access Memory) type
memory.
RAM
Amount always comes in powers of 2, so you will always see numbers like 16GB,
32GB, or 64GB of RAM, to mention some examples of memory units.
5. Graphics Card or Graphics Processing Unit (GPU)
A graphics
card is an output device that processes the data from the motherboard and
sends the appropriate information to the computer’s screen for display.
You
can connect monitors to it using HDMI, DisplayPort, DVI, or VGA connectors.
It
can also be referred to as a video or display card.
A
video card takes the burden of all the video processing from the main CPU. This
gives a computer a big boost in performance.
Because
of the large processing requirements for a gaming GPU, fans are
almost a given.
A
video card plugs into a PCI Express (Peripheral Component Interconnect Express)
slot on the motherboard. It is a serial expansion bus slot capable of high
bandwidth in two directions.
A
graphics card has a GPU (Graphics Processing Unit), the main part of a computer
system that requires cooling.
A
GPU is slower than a CPU but is designed to deal with mathematical operations
required for video rendering.
The card’s
memory amount varies depending on the manufacturer’s design.
Video
cards use GDDR (Graphics Double Data Rate) SDRAM, which is specially designed
to optimize graphics performance.
GDDR
is built to handle a higher bandwidth compared to plain DDR ram.
6. Sound Card
Most
of the time, the sound chip built into the motherboard is used for audio
output.
But,
if you are a sound enthusiast or prefer high-quality audio output while playing
a game, you might be inclined to use a sound card.
Sound
cards plug into a computer in multiple ways. It can be through USB, PCI
slot, or PCI Express x 1 slot.
External
DACs have gained much more popularity and help deliver clearer and more defined
audio or high-definition sound output.
They
connect up using an IO cable like a USB cable to your computer or laptop and
provide a line out for your speakers or headphones.
A
sound processing chip on the card does all of the audio processing and is
usually not a very powerful processor.
A
sound card can offer a wide range of connectivity with various audio equipment.
A
few examples could be optical audio, a 1/4 inch jack, or RCA connectors.
7. Hard Disk Drive (HDD)
A
hard drive is still found in many PCs to this day. A mechanical drive’s purpose
is to store all your information for retrieval at any time.
Apart
from storing information for your computer, it also functions as a boot drive
to run the operating system (OS) from it. You can install operating systems of
many different kinds depending on your needs.
An
OS is a software program that’s installed, making a computer useable, like
Microsoft Windows, for example. The biggest vulnerability of a mechanical drive
is its physically fragile nature.
One
bump the wrong way can destroy a whole drive. A mechanical hard drive contains
one or more platters that spin anywhere between 5200 to 10000 RPM (revolutions
per minute).
The
read and write heads are spaced only about 0.002 (51 micro M) inches from the
platter.
This
gives you an idea about the physical limitations of its fragile nature.
Small
areas on the platter can be arranged to represent a 1 or a 0. It can be changed
using the drive head to alter the material to represent the correct value
magnetically. This is how to write data to the drive for storage.
There
are various categories of hard drives made for various real-world applications.
Some
examples include:
- General
use for desktops or laptops.
- Gaming
optimized for desktops or laptops.
- General
high-capacity storage.
- NAS
Devices.
- Servers.
- Video
recording.
They
can also be purchased as an external drive that usually connects to your
computer by USB cable.
An
uninterruptible power supply is sometimes used to prevent data loss with
mechanical drives where a sudden power outage is experienced, or the power cord
is accidentally disconnected while the computer is running.
This
allows proper shutdowns for desktop systems that have experienced sudden power
loss.
8. Solid State Drive (SSD)
An
SSD is also a type of hard drive, but it doesn’t have any moving bits. It
consists of a bank of flash memory that can hold a reasonable amount of
information.
While
SSDs are increasing in size all the time, they aren’t cost-effective for
storing large amounts.
A
mechanical drive has a cheaper gigabyte-to-dollar ratio.
However,
the SSD is a high-performance drive. It’s fast and cannot be as easily damaged
by dropping it or taking a few bumps.
SSDs
are available as 2.5-inch laptop encapsulated drives, and an M.2 SDD is the
most commonly used kind on the market.
That’s
why I always recommend SSDs for portable-type computers where possible. In our
other article, you can read more about whether or not SSD’s are worth it.
9. Power Supply Unit (PSU)
A
power supply unit mounts inside the computer case. It converts the AC mains
supply from the power cord from a wall socket and supplies the correct DC
voltages to all the components inside the computer.
A
computer power supply supplies the following voltages:
- +3.3v: This voltage is supplied to the motherboard.
- +5V:
This voltage is supplied to the motherboard and other computer hardware.
- +12V: This voltage is supplied to the motherboard and
other components.
- -12V: This voltage is supplied to the motherboard.
It
plays an important role in keeping a computer running reliably.
You
get different wattage ratings for power supplies. The higher the wattage, the
higher the electrical current that can be made available to everything that
needs it to function properly.
The
higher you go in Watts, the more the power supply will likely cost.
A
power supply usually also comes with a cooling fan. This helps all the internal
components in your computer to stay cool when the power supply is subjected to
bigger loads.
You
read more about a power supply and its lifespan if you want to know
how long it lasts.
10. Monitor or Visual Display Unit (VDU)
A monitor is
an output device used to visualize the graphics information sent from the
computer’s GPU.
There
are various types of monitors on the market. A LED (Light Emitting Diode)
backlit LCD (Liquid Crystal Display) monitor is the most commonly used with a
modern PC.
There
are also various computer screen sizes with different aspect ratios. The aspect
ratio is simply the ratio between height and width.
For
example, a 16:9 aspect ratio computer screen will have 16 parts wide to 9 parts
in height.
There
are also curved computer monitors, but they are more expensive computer
screens.
Monitors
also have a fast response time to keep up with the high demands required to
eliminate delays with user input for gaming.
11. Keyboard
A
keyboard is an input device that is one of the ways to communicate with a
computer. Typing a key from the keyboard sends a small portion of information
to tell the computer which key was pressed.
Once
the computer receives input from the keyboard, it can use the keystrokes in
digital form to produce a specific task in any software that’s being used.
The
computer system can use this information in many ways. An example could be a
command or a character that can be used in a document.
There
are two main different types of keyboards. Mechanical and membrane types.
12. Mouse
A
mouse is an input device that allows the user to move a pointer displayed on
the monitor and experience a more intuitive interaction with computer systems.
These
days mice have more buttons than the common three and offer way more functions
than mice in the early days.
However,
the three main buttons allow the user to select, grab, scroll and access extra
menus and options.
A
computer mouse is a handy pointing device that can be wired or wireless. The
latter obviously requires batteries.
Optical
mice of today allow for very accurate precision and smooth movement.
Common peripheral components for computers
Here
are some common peripherals that connect to a computer and extend their
usefulness.
Printer
A
printer can take an image sent by a computer and deliver it onto a sheet of
paper.
It
does this by using the information from the computer, and by either using toner
or ink, it deposits one of these in a controlled and accurate manner to form
the image.
Scanner
A
scanner can take anything on paper, and it functions by scanning it to produce
a replicated digital image for a computer to save.
This
is also handy for saving physical photos you want to preserve.
Once
the photo is stored digitally, it won’t decay as a physical photo does over
time.
The
flatbed scanner is the most commonly used today.
Many
all-in-one devices, also known as multifunction devices, have printer and
scanning capabilities in one reasonably compact product.
Computer Speakers
Computer
speakers can connect to the sound card at the rear of the computer.
Another
way they can be connected is by a monitor that already has built-in speakers.
Generally,
the sound quality is poor from a monitor’s speakers. That’s why most people buy
a set of computer speakers for their desks.
You
can even connect up a 7.1 surround speaker system to certain sound cards for a
computer.
This
can add a nicer experience to gaming, playing music, or watching a film.
Conclusion
That
covers all the components of a computer system. All of these play a vital
function in a computer to make it work.
Once
you understand these basic parts to a memorable level, it probably won’t be
long until you repair or build desktops yourself.
