Common Internal Computing Components | CompTIA IT Fundamentals FC0-U61 | 2.3

In this video you will learn about the purpose of common internal computing components such as the motherboard/system board, firmware/BIOS (basic input output system), RAM, CPU (central processing unit), storage, GPU (graphics processing unit), cooling, and the NIC (network interface card).

Motherboard/System Board

A motherboard is a printed circuit board and the foundation of a computer which is the biggest board in a computer chassis.  Motherboards connect the CPU, memory, storage devices, and input and output devices to each other with a combination of built-in ports, sockets, and cables.  Motherboards are used in desktop workstations, servers, all-in-one desktops, and laptop computers.

Typical Full-Size ATX Form Factor Motherboard

SATA Ports

SATA (also known as Serial ATA) stands for Serial Advanced Technology Attachment”.  It is an interface used to connect ATA hard drives to a computer’s motherboard. Some motherboards have front-facing SATA ports used for use with mass storage devices (DVD drives, SATA hard drives, & SSD drives), while others have top-facing SATA ports.

SATA Ports

Port Cluster

Desktop motherboards have a port cluster that is visible at the rear of the system which allows for external devices to plug into these ports.

Motherboard Port Cluster

Motherboards can vary in size (known as form factors), number and types of card slots, number and type of memory (RAM) modules, the number and types of ports available from the rear of the system, and other features as well.

Expansion Slots

An expansion slot (also known as a bus slot or expansion port) is a connection or port inside a computer on the motherboard or riser card.  It provides an installation point for a hardware expansion card to be connected. Motherboards for desktop computers have at least one expansion slot, and most have three or more.  Expansion slots are used to add cards that provide additional ports or replace low-performance ports with higher-performance ports.

Motherboard Expansion Slots

Laptop Motherboard

Laptop motherboards provide the exact same functionality as that of a desktop motherboard.  The major difference is that on laptop motherboards, rather than the ports being clustered, they are attached to the edge of the laptop, and ribbon cables are used to connect the display, keyboard, and touchpad to the motherboard.  The processor is cooled by a thermal module connected to a fan.

Typical Laptop Motherboard


BIOS (basic input/output system) is a ROM chip found on motherboards that allows you to access and set up your computer system at the most basic level.  The BIOS is responsible for locating the drive that has the operating system, setting processor and memory speeds, setting ports for drives and external connections, and much more.  When you first turn on your computer, the BIOS (also known as a type of firmware) runs programs that activate essential parts of the computer. Later in the startup process, the BIOS/firmware hands responsibility over to the operating system to finish the startup process. Firmware is a software program or set of instructions programmed on a hardware device.  It provides the necessary instructions for how the device communicates with the other computer hardware. You will come across a term called UEFI (unified extensible firmware initiative) which basically refers to an enhanced type of firmware used on almost all desktop and laptop computers starting in 2014.  UEFI firmware can be navigated with a mouse or a keyboard, supports hard drives of 2.2TB and larger, and provides faster system startup as well as additional features.

Typical BIOS Setup Utility
Typical UEFI Utility

CMOS (Complementary Metal Oxide Semiconductor)

A CMOS is a technology used to produce integrated circuits.  CMOS circuits are found in several types of electronic components, including microprocessors, batteries, and digital camera image sensors.  The specific settings used by the BIOS are stored in the CMOS chip, whose contents are maintained by a small battery on the motherboard.

CMOS Battery

RAM (Random Access Memory)

Random access memory (RAM, also known as main memory, primary memory, or system memory) is a hardware device that allows information to be stored and retrieved on a computer.  RAM is a temporary storage used by apps (programs) that are run by the CPU. RAM is also a temporary storage for data being used by the apps. The contents of RAM vanish (known as volatile memory) as soon as the system is turned off, so changed and new data must be saved to a permanent storage device such as a hard drive. The amount of RAM used by an app varies according to whether the app is idle or is being used to view, create, or modify a file.  The larger the memory in a device, the more programs that can be run at the same time and the larger the data files that can be stored in memory.  When a system runs out of RAM, excess program code or data can be stored in temporary files on the system’s mass storage device (hard drive or SSD).  Adding more RAM to a system that has upgradeable memory is a good way to improve system performance because RAM is much faster than storage devices.

Types of DDR RAM

CPU (Central Processing Unit)

The central processing unit (also known as a processor, central processor, microprocessor, or CPU) handles all instructions it receives from hardware and software running on the computer.  The CPU is also responsible for running the operating system and apps (programs). Using data connections built into the motherboard, the CPU communicates with storage, I/O devices, and the temporary workspace in RAM to access specific operating system tasks and app functions as well as to save and retrieve files.

Motherboard CPU

The CompTIA IT Fundamentals exam will focus on two types of CPUs:

  • ARM processors which are used by mobile phones, tablets, and by small single-board computers such as the Raspberry Pi.
  • Processors that run Windows and macOS that use one of the following types: 32-bit or 64-bit.

The type, speed, and features of the CPU have the biggest impacts on a particular computer’s overall performance.

ARM (Advanced RISC Machines)

The ARM processor is a 32-bit RISC processor, meaning it is using the RISC (reduced instruction set computer) ISA (instruction set architecture).  ARM processors are microprocessors and are widely used in many of the mobile phones sold each year, as many as 98% of mobile phones. They are also used in PDAs (personal digital assistants), digital media and music layers, handheld gaming systems, calculators, and even computer hard drives.

System on a Chip (SoC)

A system on a chip (SoC) combines the required electronic circuits of various computer components onto a single, integrated chip (IC).  SoC is a complete electronic substrate system that may contain analog, digital, mixed-signal or radio frequency functions. Its components usually include a graphical processing unit (GPU), a central processing unit (CPU) that may be multi-core, and system memory (RAM).  This is one of the reasons as to why motherboards for desktop and laptop computers are so much larger than ARM-based circuit boards.

System on a Chip (SoC)

32-Bit Processors

A 32-bit processor is a type of CPU architecture that is capable of transferring 32-bits of data per clock cycle.  In layman’s terms, it is the amount of information that your CPU can process each time it performs an operation. You can think of this architecture as a road that’s 32 lanes wide where only 32 “vehicles” (bits of data) can go through an intersection at a time.  A 32-bit processor can also support a 16-bit operating system as well.


Laptop versions of 32-bit processors were specifically designed to use less power than those made for desktops, workstations, and servers.  They are generally not interchangeable with desktop processors, as they use different sockets and different cooling devices.


A workstation refers to an individual computer, or group of computers, used by a single user to perform work.  Workstation processors are designed to support one or more CPUs on a motherboard and to be optimized for computer-aided design (CAD) rather than gaming, as with desktop processors.  Workstation processors typically have larger memory caches than desktop processors.


A server is a software or hardware device that accepts and responds to requests made over a network.  The device that makes the request, and receives a response from the server, is called a client. Server processors are designed to perform heavy workloads, and often two or more processors are used on a single motherboard.  Server processors typically have memory caches that are larger than workstation processors.

64-bit Processors

A 64-bit processor (an Intel x86 processor that also runs 64-bit software is known as an x64 or x86-64 processor) supports both 64-bit and 32-bit operating systems and apps.  A 64-bit processor supports much larger amounts of RAM than a 32-bit processor and as a consequence can work with much larger amounts of data at the same time. Most 64-bit processors also feature two or more processor cores.  Each processor core runs like a separate processor.

32-bit Processor vs. 64-bit Processor


Laptop processors from Intel & AMD have also supported 64-bit operations for over a decade.  Laptop processors typically have smaller memory caches, slower processor clock speeds, and other optimizations for running on battery power, and they fit into different sockets than their desktop counterparts.  Laptops are more popular than desktop computers and there are a bewildering variety of laptop processors on the market.


Most Intel Xeon and all AMD Opteron workstation processors support x64.  Compared to 64-bit desktop processors, they are optimized for 3D rendering and CAD support.  Systems used for workstations usually feature 16B or more of RAM, high-end video cards made for accurate rendering, hard drives using Serial Attached SCSI (SASI) or SATA Express, and to or more 27 inch or larger displays.


Most Intel Xeon and all AMD Opteron and EPYC server processors run 64-bit operating systems and apps.  These processors are optimized for use in dual-processor or multiprocessor operations and for very high-speed networking.  Gigabit or 10G LAN support, RAID array mass storage, & optimization for media streaming and file sharing are typical features.

GPU (Graphics Processing Unit)

A GPU is a programmable logic chip (processor) specialized for display functions.  The GPU renders images, animations and video for the computer’s screen. GPUs are currently found in two places:

  • Many processors made for desktop computers as well as almost all processors made for laptops and other form factors include GPU functions.
  • For higher performance in gaming, 3D rendering, and CAD, cards with discrete GPUs are used in desktops and workstations and some gaming laptops.

If the GPU is built into the processor, the GPU typically uses a portion of system memory.  If the GPU is built into a card, the card has its own memory. Desktop computers that support CPUs with integrated GPUs have video outputs in their port cluster.  However, these computers can also use graphics cards similar to the one shown below.

High Performance GPU


Computer data storage is a technology consisting of computer components and recording media that are used to retain data.  The operating system, apps, and most data are stored in an internal drive. Two types of drives are used for system storage in desktops, laptops, and similar computers:

  • Hard drive
  • Solid-state drive (SSD)

Hard Drive

A hard disk drive (also known as a hard drive, HD, or HDD) is a non-volatile data storage device.  It is usually installed internally in a computer, attached directly to the disk controller of the computer’s motherboard.  It contains one or more spinning metal or glass platters that are coated with a magnetic substance. Read/write heads move across the platters to read, write, and rewrite data as needed.  Typical desktop hard drives are 3.5 inches wide, whereas laptop hard drives are 2.5 inches wide and are also shorter in height. Both types connect to the motherboard via SATA connections.  Typical storage capacities range from 500GB to 4TB or larger.

SSD (Solid-State Drive)

A solid-state drive (also known as SSD, solid-state device, or solid-state disk) is a device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage.  SSDs perform much faster than a spinning hard drive, however, an SSDs cost per GB is much higher than a hard drive of comparable capacity. An SSD is typically 2.5 inches wide, but some made for very small laptops are available in a 1.8 inch wide form factor.  Most SSDs connect to the motherboard with SATA interfaces. When any type of SSD is used, an internal or external hard drive can also be used to provide additional storage for apps and data.

Side Note:  A third type of drive, an SSHD, combines a small amount of SSD storage with a spinning hard disk.  It is less expensive than an SSD but provides faster performance than a spinning hard disk.



Computer cooling is required to remove the waste heat produced by computer components, to keep components within permissible operating temperature limits.  Components that are susceptible to temporary malfunction or permanent failure if overheated include integrated circuits such as the CPU, chipset, graphics cards, and hard disk drives.  Most desktop computers power supplies have built-in fans, and almost all CPUs have active heat sinks (a fan combined with a finned cooler), most systems should have additional fans installed to adequately cool the motherboard and the components connected to it.

Motherboard Fan & Heat Sink

Caution:  If a fan built into a power supply fails, the entire power supply should be replaced.  High voltages retained inside the power supply even when the power is disconnected can injure or kill anyone who attempts to replace a power supply fan.  However, active heat sinks and case fans can be replaced if they fail.

NIC (Network Interface Card)

A NIC (also known as an Ethernet card and network adapter) is a computer expansion card for connecting to a network (eg. home network or internet) using an Ethernet cable with a RJ-45 connector.  Almost every desktop and laptop computer manufactured in the last decade or more includes a network interface card or built-in wired network port. Almost all laptops manufactured in the last decade also include a wireless network card that has antennas built into the frame of the display.  Smartphones and tablets also include wireless networking. Wired and wireless Ethernet network adapters can connect to other networks and to the internet.

Wired vs. Wireless

A wired Ethernet port enables a  computer to connect to any Ethernet network.  All a user has to do is connect a network cable to their computer and the system will be recognized unless the network has been configured to accept connections from only specified devices. When a computer is connected to a network via a wired connection, signal lights on the Ethernet port indicate port speed and connection activity.  The amber light indicates that the maximum speed signal the port can use is present (Gigabit Ethernet on a Gigabit Ethernet adapter; Fast Ethernet on a Fast Ethernet adapter).  This is a steady light. The green light, which indicates network activity, blinks on and off as the network adapter sends and receives data. The signal lights do not turn on if a working connection is not attached or if the computer is turned off.

Ethernet Port on Computer

Wireless Ethernet (also known as Wireless Fidelity or Wi-Fi) requires the user to make some configuration settings on the client device:

  • Select the wireless network to connect to (any connection).
  • Provide credentials (if required, either when connecting to the network or on a web page that opens automatically).
  • Agree to conditions to use the network (common on public networks in hospitals, hotels, restaurants, etc).

Wireless Ethernet is generally slower than wired Ethernet, although the most recent implementation of Wi-Fi, 802.11ac, offers connection speeds that can exceed Gigabit Ethernet.

Wired vs. Wireless Ethernet Connection Speeds
*2.4GHz frequency band
**5.0GHz frequency band (optional with 802.11n)

When to use wired Ethernet or wireless Ethernet:

  • Wired:  when a connection with a consistent speed and a secure connection with no user interaction is needed.
  • Wireless:  when a connection is needed in areas where network cabling cannot be used and support for tablets and smartphones as well as computers is necessary.

Most recent systems with built-in wireless Ethernet also include Bluetooth for short-range data interchange with smartphones and tablets and connections to Bluetooth printers, mice, or keyboards.

Onboard vs. Add-on Card

Almost all desktops and laptops have wired Ethernet ports, but many vendors sell replacement NICs.  A NIC can provide faster connection speeds than a built-in adapter, and if the onboard adapter is damaged, installing a NIC can enable a computer to continue to be used without a trip to the repair shop.  The easiest way to add a desktop computer to a wireless network is to connect a wireless USB adapter.  You can also add a wireless USB adapter to a laptop if its built-in wireless adapter becomes damaged or is no longer suitable (too slow or not secure enough).

Typical USB Wireless Network Adapter

To add support for Bluetooth printers, keyboards, or mice to a desktop or laptop that lacks built-in Bluetooth, connect a Bluetooth adapter to a USB port.