USB or Universal Serial Bus in full is today the standard connection we see everywhere. We use it for data and for charging. But do we know enough about this universal connection?

Here is the ultimate guide to USB.


The Essence

Initially launched as a computer port back in 1996, USB is now an industry standard. We can see it literally everywhere in some form or size. The whole peripheral devices network stands today on two wails: the USB and Bluetooth.

The idea behind the USB was to create a single computer connector that would replace the many previously used connectors. The development began back in 1994. Aiming to create a universal connection and establish more straightforward software configurations for connected devices, USB took a couple of years to make.

USB wasn’t a one-man effort. It was developed by Compaq, DEC, IBM, Intel, Microsoft, NEC, and Nortel together.

In its years, it has developed a lot, becoming smaller, faster, and more powerful.

Today there are several standards and types of USB, so let’s have a look at those.

 USB Implementers Forum

The USB Implementers Forum, or USB-IF, is a non-profit founded by the companies who developed the USB specification.

 USB Implementers Forum

USB-IF is a support organization and forum for the advancement and adoption of the technology. It facilitates the development of compatible peripherals, promotes the benefits of USB, and marks the quality of products that have passed compliance testing.

Not having a USB-IF certificate does not mean that the device is terrible, to be sure. Many companies just choose not to apply, even including those behind the USB-IF itself sometimes. But if the product has acquired the certificate, the quality is guaranteed.



There are several properties based on which the USB is classified.

So, let’s start with the types:

USB-A - This is the mainly used standard for many years. Officially it is called USB Standard-A. This is also the original design for the USB. It is shaped like a flat rectangle with a rectangular interface inside to ensure the proper connection. The port and the plug differentiate between versions by the insert color and are physically mutually compatible. 

  • USB 1.0 - this is the first USB standard that came out in 1996. It supports data speeds between 1.5 and 12 Mbps. It has a white plastic insert.
  • USB 1.1 - the first widely used USB, used in the iMac in 1998. This, as it is still today, led other manufacturers to use USB on their PCs.
  • USB 2.0 - the second generation of USB was introduced in 2000 and available in 2001. It supports up to 480 Mbps data speed. It can be differentiated by the black insert color.
  • USB 3.0 - it was introduced in 2010 and increased the speed to 5Gpbs, named SuperSpeed. It features a blue insert inside.
  • USB 3.1 - announced in 2013, this one has 2 versions: Gen 1 and Gen 2. Gen 1 features the same SuperSpeed. Gen 2 features SuperSpeed+ reaching to 10Mbps speed.
  • USB 3.2 - this one brought some confusion to the namings in 2017. It also came with 2 options. Gen 1 was actually USB 3.1 Gen 1, Gen 2 was USB 3.1 Gen 2, and Gen 2x2 was the new generation reaching 20 Mbps speed. So, even today, USB 3.1 is mainly used.

USB-B - This is rarely seen today. It is mainly used to connect computers to large peripherals, like scanners or printers, though they are being replaced. USB-B is almost square in shape. 



USB-C is the latest version of Universal Serial Bus connectors. It has a shape of a rectangle with rounded corners, almost oval. It is symmetric and fully reversible, which eliminates any need for adjustments to plug. It is small enough to fit the thinnest of existing smartphones, allowing easy usage and lower cord diversity.

USB-C transfers data, power, audio, and video, replacing almost all of the currently used ports and connectors.


USB-C is available in three main versions: USB-C 3.1, USB-C 3.2, and Thunderbolts on Macs. Each of these will give you different data speeds: 10Mbps for 3.1, 20Mbps for 3.2, and 40Mbps for Thunderbolt 3.

USB-C by default, with no additional specifications and standards implemented, provides 2.5W power for charging. However, various fast charging standards are being introduced into the USB-C that allow up to 100W power delivery. These include USB PD and QC standards. I talked more about these in a previous post here.

Check out the Fast charging standards here.

Today USB-C seems to be the future of wired connections and charging. It is small, it is universal, and it is powerful. Moreover that the latest versions of USB standards are available in this format only.

USB4 - announced in 2019, this is the latest version of the USB connection. It encompasses Thunderbolt 3 specification and reaches to 40Mbps speed. 

Lightning - technically, this is not a USB. Lightning is Apple’s proprietary standard, the port seen on iPhones. It does look like USB-C and supports speeds similar to USB 3.0. 

Other parameters:

  • Mini-USB - This was a smaller variation of USB. Didn’t really stick around for a long time, being a mediocre size. It was unnecessarily small for laptops and such but too big for phones and tablets.
  • Micro-USB - This was one of the most popular USB implementations until just recently. You would meet it on the majority of smartphones. Now the USB-C is taking over, but you can still see it on several smaller devices.
different sizes of usb

Future Development of USB

Today it is evident that any future developments are going to be based on the USB-C. The latest generation of USB is available in Type C only.

However, the main problem is the lack of a single universal standard and the huge number of proprietary standards, especially in charging. Moreover, with rumors about Apple leaving the charging port out entirely on their next iPhone, this issue might stay here for a long time.

In terms of laptops and such devices, we can safely state that the trend is towards the unification of connection. The choices are going to be between USB-C and wireless connections. The latter being still unstable and easily disrupted, USB-C is the current solution.

It is safe to say that we will see an increase in capabilities and speeds in the future of USB connection format. We might also see some more universalization in terms of standards and charging speeds, although this could take more time than we’d like.


Wrap up

By the end of the day, USB is a blessing for the portable computer age, freeing us from a vast amount of cords. Still, every day we have a bunch of those cords and adapters and stuff because standards and development speeds don’t match between brands and devices. 

The dream of a universal connection combined with a universal charging solution is coming true with things going forward. Slowly, a lot slower than we’d hope, but surely.