Understanding USB Types (A, B, C, Micro, Mini) And USB Versions (USB 2.0, 3.0, 3.2, 4)

Table of Contents (click to expand)

USB cables can be classified into USB Type A, USB Type B, USB Type C, USB Micro, USB Mini, and Lightning based on their physical design. Furthermore, USB connectors are divided into various versions based on their speeds, like USB 1.0, USB 2.0, USB 3.0, and USB 4.0.

It is safe to say that almost all electronic devices, including smartphones, laptops, tablets, desktops, Bluetooth speakers, and so on, rely on USB ports and cables for various functions.

But like any technology, USB or “Universal Serial Bus” (it’s quite a mouthful, isn’t it) has evolved a lot since its inception in 1995. As such, it is sometimes difficult and even overwhelming to understand and distinguish between terms like USB 3.0 vs. USB Type B. In this example, what does “Type B” mean exactly? How about “3.0”? What does that mean?

This article will discuss all you need to know about USBs. But before we get into USBs, let’s quickly talk about a term you will always hear along with USBs – USB port.

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Understanding USB Ports

Most electronic devices have a port, i.e., where a USB cable gets plugged. That “place” or slot is called the port. As you can guess, this port allows USB devices to get plugged into the ‘host’ device.

Black removable flash disk memory in fingers with laptop USB slot on white background
A USB cable is plugged into the USB port of the laptop. (Photo Credit: Jaroslava Nyvltova/Shutterstock)

So, if you are transferring data from your phone to your laptop via a USB cable, you will plug your phone (host) into the laptop’s USB port (receptor).

A USB (Universal Serial Bus) is a standard connection interface that enables communication between devices and a host controller such as a personal computer. It is most commonly used to connect peripherals such as mice, keyboards, printers, scanners, cameras, and flash drives to a computer.

Now that you understand a USB port, it’s time to jump into USB types.

Also Read: Why Do Transfer Rates Vary When Copying A File From PC To USB Stick And Vice-Versa?

Types Of USBs (Based On Their Physical Design)

USB cables come in different shapes and designs. Therefore, based on their physical structure, they are classified as follows:

  1. USB Type A
  2. USB Type B
  3. USB Type C
  4. USB Mini (Mini USB A and Mini USB B)
  5. USB Micro (Micro USB A, Micro USB B, and Micro USB B Superspeed)
  6. Lightning cable (for Apple devices)

Here’s a picture to better understand different USB types:

Most of standart USB type A, B and type C plugs, mini, micro, lightning, universal computer white cable connectors
Different types of USB cables. (Photo Credit: iunewind/Shutterstock)

1 – USB Type A

USB Type-A connectors, or simply Type-A connectors, are one of the most common USB connectors. As such, they are sometimes also called Standard A connectors. It is the standard rectangular-shaped connector that is commonly found on one end of nearly every desktop computer, laptop, media player, TV, game console, etc.

USB Type A
USB Type A. (Photo Credit: cigdem/shutterstock)

If your laptop or desktop computer has a USB port (where you can plug in USB devices), it will most likely be a USB Type-A port. Note that most modern Apple laptops (Macs) don’t have USB Type-A ports.

2 – USB Type B

Type B is smaller than Type A and is square-shaped. It is boxier in shape compared to USB Type A. This is relatively less common than Type B, but you would find it on computer components like printers, scanners, external hard drives, etc. It has become less common since the introduction of smaller connectors like micro and mini USB, and the reversible USB Type C.

USB Type B
USB Type B connector. (Photo Credit: Hank Shiffman/Shutterstock)

3 – USB Type C

USB Type C is arguably the most popular USB connector. It is also the most recent as it was introduced in 2014. Due to its small size, it easily fits into the smallest peripherals we use today, like smartphones, Bluetooth speakers, etc. It is a standard for connecting and charging devices, known for its compact size and functionality.

One of the many advantages of Type-C over other existing variants is that it allows “reverse plug orientation,” which basically means that you can always plug in your USB cable correctly on the first try. Its plug is made so you can plug it into the slot without thinking about its orientation.

USB Type C
This is what USB Type C looks like. (Photo Credit:Mateus Andre/Shutterstock)

It’s also capable of carrying a lot of power, so it can be used to charge larger devices like laptops, in addition to smaller devices like smartphones and tablets.

Another cool thing about Type C is that it offers a bi-directional power supply; in other words, you can charge your smartphone from your laptop and vice versa.

Furthermore, USB-C supports the faster data transfer rates of USB 3.1 and can carry a video signal, making it more versatile than older USB types. Due to these advantages, it’s becoming the standard connection type for many new devices.

USB Type C made headlines in tech periodicals worldwide when a variant of Apple’s 12-inch Macbook was launched. It was the first notebook to incorporate Type-C in its design.

Type C, as mentioned before, is already widely used worldwide. As such, it is almost certain that every electronic device will support Type-C in the years to come.

4 – USB Mini (Mini USB A And Mini USB B)

USB Mini are further divided into two variants: USB Mini A (or Mini USB A) and USB Mini B. These are smaller counterparts of Type A and Type B USB connectors. They are designed for their compact size, which makes them handy for smaller devices.

USB MIni A & B
USB Mini A and USB Mini B connectors. (Photo Credit: Wikimedia Commons)

You will likely find USB Mini in portable cameras, game controllers, and some old mobile phones. They typically have 5 pin configurations and are smaller than regular USB types, hence the name ‘mini’. However, they have largely been replaced by the smaller Micro-USB and USB-C connectors.

5 – USB Micro (Micro USB A, Micro USB B, And Micro USB B Superspeed)

Popularly known as Micro USB, this is a very common USB connector you will find in many smartphones these days. They were designed for use with smaller devices, such as smartphones, digital cameras, and other portable devices. The micro USB connector is made to be more durable and stand up to the kind of abuse portable electronics can undergo.

However, with the advent of USB Type C, Micro USBs are slowly getting phased out in newer models of high-end smartphones. But Micro USB is still widely used in budget smartphones and other electronic devices worldwide.

USB Micro
Micro USB B connector. (Photo Credit: Marco Rubino/Shutterstock)

There are two types of micro USB connectors: Micro-A and Micro-B. Both have a similar width and approximately half the height of their mini USB counterparts.

There is one more variant of USB Micro, which is known as USB Micro B Superspeed. As the name suggests, this enables data transfer faster than traditional Micro USB B connectors.

USB Micro Superspeed connector
USB Micro Superspeed connector with USB Type-A on the other end. (Photo Credit: Nor Gal/Shutterstock)

As such, you will most find these connectors on external hard drives, where vast amounts of data transfer occur regularly.

6 – Lightning Cable (For Apple Devices)

Modern Apple devices, like iPhones and iPads, often have an entirely different kind of USB connector – the Lightning cable. The cable has a thin, rectangular connector on one end and a Type C connector on the other end.

Lightning cable
A Lightning cable with a thin connector on one end and a Type C on the other end. (Photo Credit: Jaromond/Shutterstock)

It is also reversible, i.e., it can be plugged in either way without worrying about which is the right side up.

It was introduced in September 2012 as a replacement for the 30-pin dock connector. The Lightning cable is significantly more compact than its predecessor.

As you can imagine, the design of the lightning connector makes it impossible to be used in any other device other than Apple devices, which makes it a nuisance for many users.

These were the main types of USB cables based on their physical design and structure.

Now, let’s look at types of USBs based on their speed and functionality.

Also Read: How Did The 3.5mm Jack On Electronic Devices Become The Norm?

Types Of USB (Based On Their Version And Speed)

There are different versions of USB based on how fast they transfer and receive data between two electronic devices. The main types of USB are as follows:

  1. USB 1.0
  2. USB 2.0
  3. USB 3.0
  4. USB 4.0

There are some versions between these, like USB 1.1, USB 3.1, and USB 3.2.

Here’s a table that lists major differences in speeds and performance of some USB versions.

Key differences between some USB versions.
Key differences between some USB versions.

USB 1.0

USB 1.0 was launched in January 1996. It was the fist version of the Universal Serial Bus (USB) standard. It specified data transfer rates of 1.5 Mbps (Low Bandwidth) and 12 Mbps (Full Bandwidth).

It ran into some issues, and a newer version, USB 1.1, was launched in September 1998. The top speed of data transfer of USB 1.1 was 12 megabits per second (Mbps).

USB 2.0

USB 2.0 was launched in 2000 and significantly upgraded the maximum data transfer speed to 480 Mbps. In addition to that, it also enabled USB to have a better (and more efficient) current capability to provide charging to electronic devices like smartphones.

USB 3.0

USB 3.0 was launched in September 2007 and could handle a top speed of 5 Gbps. This was the third major update to USB standards (the previous updates were versions USB 1.0 and USB 2.0).

However, further updates were released over the next couple of years, which triggered the renaming of USB 3.0 (i.e., the latest USB version of that time) to USB 3.1 Gen 1.

So, USB 3.0 and USB 3.1 Gen 1 are essentially the same and have a top data transfer speed of 5 Gbps. Then, in July 2013, USB 3.1 Gen 2 was released, with its top data transfer speed at 10 Gbps.

Then, in September 2017, USB 3.2 was released. There are four versions of USB 3.2: Gen 1×1, Gen 1×2, Gen 2×1, and Gen 2×2.

USB 3.2 Gen 2×2 is quite popular nowadays and offers a top speed of 20 Gbps using 2-lane operation (hence the name 2×2). This version is only compatible with USB Type C design. Since it offers considerably faster data transfer and charging speeds, most modern smartphones and even some laptops support this USB version.

USB 4.0

The latest and most modern USB version is USB 4. It was launched in 2019 and offered a formidable upgrade above its previous versions. It only uses Type C connectors and offers a staggering top speed of 40 Gbps.

USB 4.0
This is what the plug of USB 4.0 looks like. (Photo Credit: Victor Josan/Shutterstock)

USB 4 and Type C connectors look almost identical, so, naturally, many users confuse the two and interchange the terms “Type C” and “USB 4”. Note that USB Type C refers to the physical design of USB connectors. In contrast, USB 4 denotes the USB version. USB 4 has nothing to do with the shape of the connector; it just indicates the performance and speed of the USB version.

In a nutshell, USB connectors are classified based on their physical design – Type A, B, C, and so on, and their speed and functionality – USB 1.0, USB 2.0, USB 3.0, and USB 4.0.

References (click to expand)
  1. USB Type-C® Cable and Connector Specification. The USB Implementers Forum
  2. USB-C Protocol - ecee.colorado.edu:80
  3. What you need to know about USB-C | IT Support Blog. The University of Texas at Austin
  4. A Rogers. AN1953 - Microchip Technology. Microchip Technology Inc.
  5. Cable Connector Guide. The College of William & Mary
  6. Son, K., Choi, S., Jung, D. H., Kim, K., Park, G., Lho, D., … Choi, S. (2019, October). Design and Analysis of a 10 Gbps USB 3.2 Gen 2 Type-C Connector for TV Set-Top Box. 2019 IEEE 28th Conference on Electrical Performance of Electronic Packaging and Systems (EPEPS). IEEE.
About the Author

Ashish is a Science graduate (Bachelor of Science) from Punjabi University (India). He spearheads the content and editorial wing of ScienceABC and manages its official Youtube channel. He’s a Harry Potter fan and tries, in vain, to use spells and charms (Accio! [insert object name]) in real life to get things done. He totally gets why JRR Tolkien would create, from scratch, a language spoken by elves, and tries to bring the same passion in everything he does. A big admirer of Richard Feynman and Nikola Tesla, he obsesses over how thoroughly science dictates every aspect of life… in this universe, at least.

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