Motherboard
The main circuit board of a computer
Processor
The chip on the motherboard which processes the basic instructions to run the computer
- Desktop computers typically have a removable processor.
- On laptop computers the processor is usually part of the motherboard, and cannot be removed.
Memory
A computer uses RAM (random access memory) to store information temporarily, and make it available to the processor.
RAM can be quickly accessed and its data changed, but it is volatile – it only retains data while the computer is switched on.
Most computers use one or more RAM modules; each module is a small circuit board which fits into the motherboard.
Below is a RAM module from a desktop computer (left) and a laptop (right).
There are many different types of RAM, some of which look very similar, but are not always compatible with one another.
Disk
A disk is used for storing data. The data is not volatile - it stays on the disk even when power is switched off.
There are two main types of disk - spinning drives (also called hard disks) and solid state drive (SSD). Since Windows 10 it is highly recommended to use SSDs, as they are much faster.
Standard disk form factors:
- 2.5 inches (used for laptops; most SSDs for desktops are also this size)
- 3.5 inches (used for spinning drives in desktops and servers)
Disks are connected to a motherboard using either a SATA or SAS cable.
SATA is used in laptops and desktops.
SAS is used mostly in servers, and supports writing to multiple disks at once.
SATA cables and connectors look like this:
Many laptops come with an SSD which uses the M.2 form factor; this is a type of solid state drive which plugs directly into a slot on the motherboard; it is faster than SATA.
M.2 drives
The power supply
Desktop computers and servers come with an internal power supply, which converts AC (alternating current) from a wall socket into DC (direct current), to power the computer.
The most common type of desktop power supply is called ATX:
The power supply uses connectors like this to supply power to the motherboard and other components:
A laptop computer comes with an external power supply like the one below, which converts AC into DC.
Different manufacturers use different power supplies, which are often designed to work only with a certain brand or model of laptop.
Some laptop computers are now powered by USB-C.
Port interfaces
Video: VGA, DVI, HDMI, DP
Communication: USB, Thunderbolt.
Notice that the USB-C connector can transmit USB signal (2.0, 3.0, 3.1, 4) as well as other signals (DisplayPort, HDMI, Thunderbolt).
Lightning is the Apple connector. It supports a higher power output.
Lightning and USB-C connectors can be inserted either way.
Theoretical rate in Mb/s
|
Usb3.2 |
20000 |
|
Usb3.1 (ou 3.1 Gen2) |
10000 |
|
Usb3.0 (ou 3.1 Gen1) |
4000 |
|
Usb2 |
480 |
|
thunderbolt 1.0 |
10000 |
|
thunderbolt 2.0 |
20000 |
|
thunderbolt 3.0 |
40000 |
Network: Ethernet, WiFi
Most laptops, desktop computers and servers have a built-in Ethernet port (also known as an RJ45 port), which is used to connect to a wired network:
Desktop computers don't usually have a built-in WiFi card.
It's possible to buy a card which can plug into a slot on the motherboard (below), or connect via a USB port.
Most laptop computers have a built-in WiFi card.
It can typically be accessed by removing a cover on the bottom of the laptop, or by removing the keyboard.
You can recognise the WiFi card because it has two antenna cables connected to it, as you can see in black and white below; these cables usually lead to the back of the laptop screen.
