What is a Motherboard? – PC MOBO

If you have ever been curious enough to take a peek inside the computer you may have seen something that looks quite complex. Lots of tiny components that seem expertly placed and minute lines of varying lengths and sizes that seem to connect them all. What you saw was a specialized Printed Circuit Board (PCB) known as a motherboard. So what is a motherboard?

A motherboard is in many regards, a PCB. But this is an over-generalization. A motherboard, also known as a MOBO or mainboard, is a complex circuit board that houses other hardware components and various inputs/outputs for expansion.

A motherboard happens to be the most important part of a computer (among other things) as it holds some of the vital components like the CPU and the RAM that the computer needs to function.

It should be noted however, that a motherboard as a circuit an concept is not just limited to computers, other devices like mobile phones, printers and even washing machines. But the common nomenclature refers to the motherboards found in these devices as “main boards”.

Also Read: Motherboard vs Circuit Board

What is a Motherboard?

As mentioned earlier, a motherboard is the main circuit board of a computer. It is the primary circuit that allows communication between the various components of a computer.

A motherboard offers a lot of expansion capability. With this, it allows you to install a myriad of components which include, but are not limited to, micro processor, RAM, video cards, sound card, hard drives etc.

It is also interesting to note that the components that are installed on top of the motherboard like video cards and sound cards are called daughterboards.

Another critical feature of a mother is its many input and output protocols. A motherboard comprises of sockets, network controllers, disk controllers, USB Controllers, PCIe expansion protocol, and video output controllers with ports like HDMI, VGA etc

This allows you to connect a plethora of peripherals such as mouse, keyboard, printers etc.

Also Read: Best Motherboards with WiFi

What Makes Up a Motherboard

Most modern computers, except for certain embedded systems, are modular thanks to their motherboards. This means that you can take out certain components and replace them with other compatible ones.

This lets users customize their computers by adding newer and powerful components into their motherboards.

A motherboard houses parts of the computer such as:


What is a Motherboard
CPU socket and processor on the motherboard. Motherboards have different sockets for supporting different models of CPUs.

Motherboards will come with a socket that can be fitted with a compatible processor. The CPU socket consists of connectors like pins that form the link between the CPU and the motherboard.

Since CPU sockets are not all cross-compatible, some of the top chip manufacturers like Intel and AMD have their proprietary socket types that fit their devices.

Furthermore, the same manufacturer may produce different socket types for different CPU tiers, like Intel has the LGA 1151 socket for mainstream computers and the LGA 2066 for high-end desktops.

In many cases, the motherboard you have will dictate the kind of CPU you can have on your computer.

In other cases, the motherboard comes with a non-removable CPU. Motherboards with soldered CPUs are quite common on laptops whereas socketed CPUs are the norm on desktop computers.


DIMM Slot 2
DIMM Slot house the RAM.

The motherboard will always have a Dual In-Line Memory Module (DIMM) slots commonly known as RAM slots. It may be removable and some may be soldered onto the motherboard.

Besides the CPU, RAM is another crucial component your PC won’t work without it.

RAM happens to be the main memory for your device. All programs that you run, including the Operating System are first loaded onto the RAM before you can start running them.

Many motherboards have more than one RAM slot. However, that doesn’t give you the liberty to go mixing and mis-matching them. There are a few caveats you may need to consider first. You need to know the type of RAM you’re using.

I won’t go so much into detail about this as there are several types of RAM. Nevertheless, RAM slots on the motherboard are not universal. It is, therefore, crucial to know the kind of RAM your motherboard supports.


m.2 slot
m.2 slot for SSDs

Your computer will need adequate storage to function. With many motherboards, you get a hard disk slot. Here you can add a hard drive in which all your software and data will be stored by the PC.

These slots were formerly in the shape of Integrated Drive Electronics (IDE) interface, but they have been replaced by Serial Advanced Technology Attachment  (SATA) slots for a long time now.

While the SATA slot is situated on the motherboard, the hard disk is connected via a SATA cable.

Advancements in technology have seen the development of faster storage, the likes of Solid-State Drives (SSDs).

These are much faster because unlike conventional hard drives, they don’t make use of any moving parts thus reducing the latency in reading and writing data to the disk.

Therefore, on the newer motherboards, you also get M.2 slots that are capable of supporting the latest SSD drives.

Ports and PCIe

PCIe slots come in x16, x 8 and x4 bandwidth sizes

These are the interfaces that connect us to our PCs. Ports on a motherboard let us do more than just share data and resources. They also let us extend the power of the computer.

Through interfaces like the Express Card slot, a user can insert various Express Cards into the computer and use them to perform different functions.

Ports such as the high-speed PCI Express (PCIe) let users connect devices like graphics cards, SSDs, network cards and sound cards to the motherboard allowing faster graphics processing capability, better read and write speeds which in turn translates to faster PC performance.

Through the use of ports, we also get access to networking capabilities. The more common USB and Ethernet Ports serve this purpose on many devices.

Other Peripherals and Chips

A small ROM that contain BIOS

Motherboards contain lots of components that serve numerous different purposes.

Some motherboards come with a slot on which you can attach a graphics card. Slots for this include the aforementioned PCIe slot as well as the legacy Accelerated Graphics Port (AGP).

There’s also a chip known as the ROM. This chip contains the firmware which has all the necessary instructions needed by the computer to boot. The software contained in the ROM chip is what is referred to as the BIOS.

Let’s not forget about power. The motherboard contains connections that handle the supply of power to all the components mentioned above. And since the pc will generate a lot of heat during operation, most motherboards also come with a fan and its control.

Also Read: Best Motherboards with M.2 Slots

Final Words – So What Does a Motherboard Do?

A motherboard makes use of the components it is given to provide a user with output from the various input it’s provided with. Basically it is the bridge that connects all the components together.

It forms the connection between all the components of the computer, allowing the processor to access all the resources it needs to perform its functions.

During operation, data is constantly moved from storage to RAM, programs are constantly being executed and the physical interfaces like keyboards and mice are constantly providing the computer with input. Motherboards facilitate this.

What the motherboard does is: it orchestrates the connection between all these components, allowing the CPU to run optimally.

In conclusion, if you ever ask yourself what is a motherboard again, just remember that the best analogy to here is that it serves as a highway for all the data that passes through a computer and its many components.

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