Before 1995, most computer peripherals like mice and keyboards featured mini-DIN connectors. Universal Serial Bus (USB) released in 1995 and changed computers forever.
The USB Implementers Forum (USB-IF) was created by Intel in collaboration with other companies to fuel USB adoption.
In simple terms, USB is a collection of connectivity specifications enabling power and data transfer between electronic devices.
Such an industry standard enables computer peripherals and other electronics to automatically work across billions of devices in plug and play fashion.
Billions of USB products hit the market on an annual basis. These days, virtually all computers and laptops feature USB ports.
USB is utilized in everything from mice and keyboards to storage devices and charging cables. No other connectivity standard has had a greater impact on computers, and it won’t disappear anytime soon.
USB-IF continues to develop and improve the USB standard. On the horizon, the world can expect various speed and power improvements.
In this article we will examine the various USB types, categorized by their data transfer speed and size/dimensions.
Table of Contents
USB Types By Speed
Different versions of the USB specification range from USB 1.x to USB 3.1 and beyond (there is even a USB4 version introduced in 2019).
These USB types describe data transfer speeds and technical specifications. Typically, an increased data transfer rate marks the main difference between generations.
Other things like power consumption and power availability change from time to time as well.
USB 1.0 reached the market in January 1996 with limited data speeds. At maximum speed, the standard managed 1.5 Mbit/s speeds and couldn’t accommodate extension cables.
Adoption rates for USB 1.0 fell flat due to power limitations and a handful of other issues. However, USB 1.1 hit the market in August 1998 and ushered in the USB era.
Millions of people adopted the standard at that point. This version of the standard featured 1.5 Mbit/s low speed up to 12 Mbit/s full speed. At the time, USB led to manufacturers removing legacy ports from computers.
USB-IF formally ratified the USB 2.0 specification in 2001. By design, USB 2.0 kept the USB 1.x low and full speed bandwidth range.
A maximum speed of 480 Mbit/s was implemented into this version of the standard, though. Various improvements and additional solutions accompanied USB 2.0.
For instance, the mini-A and mini-B connectors came into existence as did USB On-The-Go. A new battery charging specification allowed dedicated chargers to exist.
Higher current enabled 1.5A charging speeds on devices, too. USB 2.0 further enabled the connectivity standard to explode in popularity.
The USB 3.0 specification was first described in November 2008. By 2010-11, USB 3.0 devices started to hit the market for consumers and businesses.
A number of notable improvements found their way into the updated standard. This included everything from faster data transfer speeds to lower power consumption and higher power output.
Fortunately, USB-IF made the standard backwards compatible with USB 2.0 A maximum transfer speed of 5.0 Gbit/s outpaced previous generated exponentially.
Benefits associated with USB 3.0 speak for themselves. The standard has seen widespread adoption in computers and peripherals since initial release.
July 2013 saw the release of an updated USB 3.1 standard. This particular version of the standard is broken down into either Gen 1 or Gen 2.
In this case, speed is the main differentiator between the two classifications. Gen 1 relies on the original USB 3.0 SuperSpeed specification with a maximum speed of 5 Gbit/s.
Users should consider it a rebranding of USB 3.0. On the other hand, USB 3.1 Gen 2 features SuperSpeed+ with 10 Gbit/s data rates. Transfer rate increase is the main selling point of Gen 2, specifically.
In 2019, the newest SuperSpeed+ and Thunderbolt 3 USB4 standard was proposed. This one can reach speeds of 40 Gbit/sec.
USB Types By Size and Connector
Of course, various connectors and ports are required in order to make the USB standard work. Individual ports run on a given USB specification and port type.
Then peripherals feature the USB specification and a compatible connector type. Currently, USB Type-C is the popular all-purpose connector and port. Various ports and connectors utilize the USB standard to connect devices and peripherals, though.
We will use the following schematic for each different type by size:
Perhaps no other connector is more popular than USB Type-A. Most computers and laptops feature a USB Type-A port.
Similarly, most USB cables rely on a Type-A connector at one end. Everyone knows what a USB Type-A port or connector looks like, whether they know its name or not.
Mice, keyboards, charging cables, and countless other cables utilize a Type-A connector on one end.
Computers may feature two to five or more Type-A ports for peripherals. Although different USB specifications feature different pin setups, the actual Type-A shape remains the same.
USB Type-B typically finds its way into printers and scanners. For better or worse, the Type-B connector and port isn’t nearly as common as Type-A.
Some people even refer to it as the printer connector. Calling this particular connector the least common USB type wouldn’t be a stretch. Regardless, Type-B carries both power and data or just power based on specific usage requirements.
While Type-B can be considered the printer cable, Mini-USB is best described as the digital camera cable.
In 2000, Mini-USB released alongside the USB 2.0 specification. Both Mini-A and Mini-B connectors were commonplace in the early to mid-2000s.
Early digital cameras, smartphones, and even tablets relied heavily on Mini-B for data transferal. Before too long, Mini-B gained prominence over the Mini-A connector, and the latter basically vanished.
USB-IF released Micro-USB connectors in January 2007. At release, they measured half the thickness of Mini-USB connectors.
Such a small size made these Mini-A and Mini-B connectors incredibly popular. An overwhelming majority of smartphones and cameras featured Micro-USB ports.
Similar to Mini-USB, the Micro-B port and connector won out over Micro-A. Connectors commonly allowed for both data transfer and device charging at high speeds.
USB Type-C released in 2014 and is considered the ultimate connector and port. Type-C is a reversible connector that’s considered future-proof.
Unlike previous USB connectors, users no longer need to pay close attention to plugging devices in. The cable features the USB 3.1 specification with advanced data rates and power delivery.
24 pins are housed within the double-sided connector for ultimate flexibility. When USB-IF announced USB-C, this new connector received widespread acclaim. A more flexible and powerful connector isn’t available at this point in time.
From computers and mobile devices to peripherals and charging cables, USB is everywhere. USB 2.0 remains in widespread use today but is being phased out over time in favor of USB 3.x and beyond.
The USB-A connector continues to take up real estate in computers and laptops as port options. Plus, Micro-B hangs on due to how popular the port is for older smartphones and tablets.
USB-C continues to make steady gains in adoption rate and is the gold standard of connectors.
USB is everywhere, and it’s not going away in the near future. In the end, the average person utilizes multiple USB ports and peripherals every single day.
Consumers couldn’t charge their devices or use their computers without USB standards and connectors. It remains to be seen what other developments are made related to USB.
Then again, USB-IF continues to develop faster data transfer speeds and power delivery capabilities. The USB Type-C connector probably won’t change much, but the underlying capabilities will.