Computer ports and connectors - daisy chained computers

Computer Ports and Connectors

Computer ports and connectors can be a little tricky to understand, like which cable goes where and which one does what. It won’t surprise me to know that someone somewhere cant tell the difference between computer cable connectors. If you’re such a one, take comfort because luckily, its not a life threatening disease. We have a cure 🙂

So let’s get this party started.



Well, I don’t think you had this in mind?

Image of a sea port with ships docked onto it – illustration of devices plugged into a computer via the various port types

Neither did I, but we can have it in there all the same – just because its a pretty picture.

The choice of ports may pass as a trivial matter to some when purchasing a computer, more so a laptop, but the true impact of that is felt later. Often times, laptops suffer from inadequacy of ports as compared to desktop computers. However, what we shall cover here shall be beneficial to you whether you want to get a desktop or a laptop.

So, what exactly is a port?

A port is the interface between a computer and other computers or peripheral devices, such as mice, keyboards, etc.

How many port types are there?

There are 16 different types of ports, thought some of these are obsolete and rarely find use in today’s computing. The main computer ports and connectors that you expect to find in computers today include:

  • Video Graphics Array (VGA) port
  • DIgital Video Interface port (DVI) – also included are mini-DVI and micro-DVI ports
  • DisplayPort
  • High Definition Media Interface (HDMI) port
  • USB port – Include Type A (USB 1.1, USB 2.0 and USB 3.0, USB 3.1, USB Type C)
  • RJ-45 Ethernet port

Input and output computer ports and connectors

There are several input/output ports in a computer, some however limited to only outputs.

  • Input / output ports include USB ports, audio/mic combo jack, Ethernet port and SD and micro-SD card readers.
  • Output ports are mainly used for display purposes. These include HDMI, DisplayPort, VGA and currently USB Thunderbolt ports.

What ports do I need for my laptop?

The most fundamental computer ports and connectors you would need include: a HDMI port, DisplayPort and several USB ports ( USB 3.0, USB 3.1, USB 2.0). With these, you’ll be able to do anything from connecting an external display to your computer or charging your tablet.

Let’s dig a little deeper to find out more about computer ports and connectors


This is the oldest port in use in today’s devices. It is a D-sub connector is colored blue and consisting of 15 female pins in 3 rows and screws to hold it in place. You’ll find it in projectors, CRT monitors and some LED and LCD monitors.

VGA carries analogue signal to a maximum playing resolution of a little over 2048 x 1536 px @ 85Hz, but on any modern displays it just won’t look clear and sharp. Use anything else if you can.

Desktop replacement laptops often come with VGA ports, though they are gradually being replaced with HDMI and DisplayPort.

Image of a VGA port on purple computer


Designed with an aim to replace VGA, DVI is a high speed digital interface between a display controller and a display device such as a monitor. It is vastly superior to VGA, and has screws just like VGA though being slightly larger. It comes in three main types of connectors based on the type of signal it can carry: DVI-I, DVI-D and DVI-A.

Image of DVI-I Dual Link (Top) and DVI-D Dual Link (Bottom)

DVI-I is a DVI port with Integrated analogue and digital signals.

DVI-D supports only Digital signals and DVI-A supports only Analogue signals.The digital signals can be either single link or dual link where a single link supports a digital signal up to 1920X1080 resolution and a dual link supports a digital signal up to 2560X1600 resolution.

It has a few drawbacks though – it does not support the same variety of color spaces, nor does it carry audio and data along with video.

Image of DVI connector type: DVI-I, DVI-D and DVI-A
Image of DVI connector type: DVI-I, DVI-D and DVI-A


There are currently three standards of HDMI connectors that come in devices today, i.e HDMI 1.4, HDMI 2.0 and HDMI 2.1.

HDMI 2.1 is new to the market and can support up to 10 K resolution. However, HDMI 2,0 and 1.4 are the more common types that you’ll find in consumer products.

Don’t let the version numbers get you confused thought. They only refer to the HDMI connections in your gear (TV, laptop, etc). Which is to say, your TV can come with HDMI 2.1 inputs but your HDMI cable is just an HDMI cable. As long as it is a High-speed cable, it’ll do.

Image of a HDMI Port in between a USB and VGA port

Now, lets talk about HDMI cables.

There are only four types of HDMI cables for the home:

  • High-speed with Ethernet (Category 2)
  • High-speed without Ethernet (Category 2)
  • Standard-speed with Ethernet (Category 1)
  • Standard-speed without Ethernet (Category 1)

Standard-speed cables are rated to supports 1080i (1929 x 1080 pixels – interlaced scan), although most can support up 1080p (1920 x 1080 pixels with progressive scan). The difference is the scan type.

High-speed cables on the other hand can support way over 1080p, up to a resolution of 3,840×2,160/24, i.e. 4K at 24 frames per second.

The difference in cost between a category 1 cable (Standard speed) and a category 2 cable ( High-speed) is negligible, so there’s no need under heaven to buy a Standard-speed cable today. It’s also not necessary to purchase a high-speed cable with Ethernet since very few devices currently use this.

High Speed HDMI Cable with Ethernet

So when you’re buying a HDMI cable next time, make sure you buy one indicated as High-Speed. That will be enough for all your 4K display needs.

HDMI 1.4 port and HDMI 2.0 port: What is the difference?

The main difference between the two standards is how much each data each can handle.

HDMI 1.4 can handle:

  • 1080p (FHD) at 60 Hz
  • 2160p (UHD) at 30 Hz
  • 1080p (3D) at 120 Hz.

HDMI 2.0 on the other hand can handle a lot more data. It is the go-to cable for HDR and 4K displays.

It is sufficient for handling:

  • 1080p (FHD) at 120Hz HDR
  • 2160p (UHD) at 60 Hz HDR

Find out more here.

So, what is HDM mainly used for?

HDMI is the de-facto connection for home entertainment systems and is used widely on HDTVs as an AV interface; ie between your TV and Blue-ray player or cable box. They are also quite prevalently used to connect monitors to CPUs, along with DisplayPort and DVI.


There are three standards of the DisplayPort: DisplayPort 1.2, DisplayPort 1.3 and DisplayPort 1.4.

DisplayPort 1.2: supports 4K display at 60 Hz, supports multi video streams, audio, network along with other data signals, stereoscopic 3D and 21:9 aspect ratio.

DisplayPort 1.3 on the other hand offers all that DP 1.2 does, and goes further to support 8K display @ 60 Hz, 4K stereoscopic 3D and Adaptive Sync to eliminate lag and screen tearing in games.

DisplayPort 1.4 support 5K displays (5120 x 2880) @ 60Hz refresh

DisplayPort to hub with DVI, HDMI and VGA ports

Unlike HDMI, DisplayPort cables have a locking connector thus less prone to disconnection in case the cable or device is moved.

DisplayPort hub – able to connect multiple display to a single video output

DP comes with several advantages. These include higher performance capability, the availability of display adapters for legacy display types (such as DVI, VGA and HDMI) and also the ability to connect multiple displays to a single video output.

When enabled with DisplayPort’s Multi-Stream feature, several monitors can be connected to a single output on a video source device (such as a laptop or computer), using a daisy-chain or hub configuration.

DisplayPort further supports multi-channel audio and many advanced audio features. DisplayPort to HDMI adapters also include the ability to support HDMI audio.

How has the adoption of Thunderbolt affected DisplayPort?

“Thunderbolt takes advantage of DisplayPort technology, and Thunderbolt Hosts (such as notebooks and personal computers) are backward-compatible with DisplayPort cables and DisplayPort monitors. This means you can plug a DisplayPort monitor into a Thunderbolt computer output, using a standard DisplayPort cable. The adoption of DisplayPort technology by Thunderbolt has helped to accelerate the adoption of DisplayPort in high-end computing and video post-production.” – Source

Thunderbolt port

Of all the computer ports and connectors we review in this article, the Thunderbolt 3 port is, without doubt, the King of the Hill.

There are several standards of this port, the latest of which is the Thunderbolt 3. You can read about the previous version (Thunderbolt 2.0) here.

Thunderbolt 3 is the smallest yet most powerful port there is in the market today. It comes in a Type-C connection, the type of port connection you may have in your iPhone.

Type-C port in an iPhone

It offers the fastest transfer speeds of up to 40 Gbps (double what Thunderbolt 2 offers), can support two 4K displays (4096 x 2160 30bpp @ 60 Hz) and is compatible with USB 3.1 cables and devices.

When it comes to display, it is compatible with existing DisplayPort displays, devices and cables, as well as with HDMI, DVI and VGA displays via adapters. Simply put, this is the hottest thing out there.

However, devices that come with with this port are quite costly, well beyond the reach of most consumers especially when it comes to laptops. Well, if it cannot fit into your budget now, don’t kill yourself over it. There are plenty of options out there – such as the ones we mentioned earlier – that will serve you just fine for now.

Read more on ports here

USB Type-C merges all DisplayPort, power cable and various version of USB into one cable - Computer ports and connectors
USB Type-C merges all DisplayPort, power cable and various version of USB into one cable

USB Ports

To conclude out article on computer ports and connectors, let’s have a look at the well know USB port.

There are currently four versions of USB ports. These are USB 1.1, USB 2.0, USB 3.0 and USB 3.1.

Realesed in 1998, USB 1.1 is more or less phased out, barely being used in devices today.

USB 2.0 on the other hand is still very common in computers and other devices. It has a transfer speed of 480Mbps and is backward compatible with USB 1.1. It is mainly used for low speed peripherals such as mice and keyboards, and is commonly found in desktop replacement laptops and desktops. You can identify it by its black color.

USB 3.0 (Type-A) next to two USB 2.0 Ports colored black.

Unlike the other two ports, USB 3.0 is colored blue and has a faster transfer speed of 5Gbps . It’s the most common USB port in computers today. For day-to-day users with low transfer needs, this port is more than sufficient.

Finally, USB 3.1 ports are the most elite ports in computers today. They have a transfer speed of 10 Gbps and are backward compatible with USB 2.0 and USB 3.0. They often come in USB Type-C port design. Don’t confuse this with Thunderbolt 3.0.

A USB 3.0 port (Type-C male) next to a Thunderbolt 3 port (Type-C) - Computer ports and connectors
A USB 3.0 port (Type-C male) next to a Thunderbolt 3 port (Type-C)

While both come in a type-C design, Thunderbolt 3.0 is by far superior, offering a transfer speed of up to 40 Gbps. You can tell between the two with the bolt sign on the Thunderbolt 3.0 port. Expect to find this port only in premium laptops such as the the Macbook Pro. So if you’re often transferring data from your computer to other devices, they you best consider a machine with USB 3.1 or Thunderbolt 3.0 port depending on your budget.

Top speedMax power outputPower directionCable configuration
USB 1.112MbpsN/AN/AType-A to Type-B
USB 2.0480Mbps5V, 1.8AHost to peripheralType-A to Type-B
USB 3.0 / USB 3.1 gen 15Gbps5V, 1.8AHost to peripheralType-A to Type-B
USB 3.1 / USB 3.1 gen 210Gbps20V, 5ABi-directional / Host to peripheral (compatible)Type-C both ends, reversible plug orientation / Type-A to Type-C (compatible)


Different types of USB connectors
Different types of USB connectors

See also:

Acer Aspire V5-591G-55PV Laptop Specs

Edwin M

Professionally a Mechanical Engineer and a Tech Nerd at heart, Edwin is above all a passionate hobby guitar player and proud gospel music listener. He writes reviews of gadgets he would love to buy and recommend.