USB cables are often kept on hand in people's homes or offices, and many people find that they only need to pack one connector cable with them when they travel.
Universal Serial Bus, or USB as it is commonly known, was first designed to help connect computers with peripherals, such as displays, keyboards and storage devices. Since its inception, USB has been an industry standard for the exchange of data and power between electronics. One of the only exceptions to this has been the Apple suite of products, which have been designed to support a Lightning connector since 2012. But, in 2023, Apple released smartphone products with USB-C compatibility.
Before the introduction of USB, computer users had to rely on various port configurations to establish communication between devices; these could include parallel ports, serial ports or game ports. The creation of USB made it possible to replace these different interfaces with a single connector, one that is now the default choice for most electronic devices today.
The initial USB 1.0 design has since undergone several transformations, culminating in today's USB4 version that was released in 2019. This latest iteration features a single USB connector type, USB-C, that has replaced the legacy USB connectors Type-A and Type-B, which were used for upstream and downstream communication respectively. USB Type-C has a better data transfer rate than its predecessors, which has made it increasingly popular. USB4 was designed to retain compatibility with the previous ecosystem of USB devices as well.
With so many technology products now configured to support USB-C, a single charging cable or C connector can be used across multiple devices. This compatibility makes USB technology -- and specifically USB-C -- the standard choice for consumers around the world. But what exactly is USB?
What is USB?
USB technology is used as a connector between devices for both data transfer and power delivery. It can come in the form of a USB flash drive, which can be plugged into different computers to both download and upload information, or USB cables, which can plug into a power supply or directly link two different devices, such as laptops and digital cameras or video game consoles and joysticks.
Connecting two devices lets users share information directly between them without the need to transfer data over a network. Due to the ubiquity of USB, most devices now feature dedicated USB ports. Previous port iterations have been phased out over the years.
The USB interface doesn't require user configuration, which means that users can simply "plug and play" and not worry about adjusting any device settings. Peripheral devices can connect to almost any USB receptacle, which makes it a popular choice for consumers with many devices who don't want to store numerous different cables.
USB can also replace traditional power cables for smaller devices. These devices can be plugged in, unplugged and swapped without needing to shut down the host computer. This makes use seamless and accessible, even with younger or less tech-savvy people.
The USB standard does have some limitations. By design, USB cables can only reach a certain length as they were intended to connect two devices in close proximity, rather than travel between rooms. To traverse longer distances, USB ports must be connected to a gateway. Additionally, USB data transfer rates are slower than some of the other methods available, such as Ethernet. Finally, legacy USB connectors, such as Type-A or Type-B, don't work with most modern devices. There are converters that work between legacy interfaces and USB-C, but they don't work for every device.
History of USB
- 1995. Seven companies came together to begin developing USB in 1995: Intel, Microsoft, IBM, NEC, Nortel, Compaq and DEC. Later that year, Ajay Bhatt led a team at Intel that created the first integrated circuits to support USB.
- 1996. USB 1.0 was launched in January 1996. It specified signaling rates of either 1.5 Mbps, which was considered low bandwidth or low speed, or 12 Mbps, which was the full-speed option. USB 1.0 did not support extension cables. Only standard-sized Type-A and Type-B connectors were offered. It was not widely adopted on the commercial market.
- 1998. USB underwent its first upgrade to USB 1.1 in August 1998. This was the first iteration of USB that was widely adopted.
- 2000. USB 2.0 launched in 2000, offering greater transfer speeds with a new maximum signaling rate of 480 Mbps. The 2.0 version also introduced new Mini-A and Mini-B connectors in addition to the Type-A and Type-B connectors of 1.x, as well as the ability to support battery charging.
- 2007. The new Mini connectors were revised and replaced in 2007 by Micro-A, Micro-AB and Micro-B connectors. USB devices were also enabled to communicate directly with each other without a separate USB host through the introduction of USB On-The-Go technology.
- 2008. The management of USB was transferred from USB 3.0 Promoter Group to USB Implementers Forum (USB-IF) in November 2008, the same month that USB 3.0 was first launched. USB 3.0 saw the introduction of USB SuperSpeed, which enabled a data transfer speed of 5 Gbps, as well as backward-compatible plugs, receptacles and cables.
- 2013. USB 3.1 was launched in July 2013 in two different variants: Gen 1 and Gen 2. Gen 1 supported the original SuperSpeed operation mode, while Gen 2 was designed to support a new SuperSpeed+ mode of 10 Gbps.
- 2014. A new connector type -- USB-C -- was introduced in 2014 with a higher data and power transfer rate.
- 2017. USB-IF launched the next iteration of USB 3.0, 3.2, in September 2017. This version maintained the operating modes of USB 3.1 but added two new modes with the new USB-C Fabric: 10 Gbps and 20 Gbps. This bandwidth increase was made possible through the new USB-C connector.
- 2019. USB4 was first released on Aug. 29, 2019, by USB-IF. Based on the Thunderbolt 3 protocol, USB4 is compatible with Thunderbolt 3 and backward-compatible with both USB 3.2 and USB 2.0. Data transfer speeds increased to up to 40 Gbps.
- 2022. USB4 2.0 was introduced with the ability to support speeds of up to 80 Gbps over USB-C.
Why is Apple changing from Lightning to USB-C?
Despite the popularity of USB across the globe, technology giant Apple was one of the few companies to resist its design. Since 2012, Apple has made all its devices compatible with Lightning chargers and cables -- an upgrade over its previous 30-pin dock connector. Part of the appeal was the Lightning cable's reversible ends. Users could plug an iPhone or other product into the cable without needing to worry about its orientation. This made it user-friendly and, therefore, a popular attribute of Apple products.
When USB4 was introduced, its USB-C connector featured the same reversible ends as the Lightning connector. While this didn't make it an upgrade on its own, it eliminated that advantage for Apple. On top of that, USB4 is capable of much faster data transfer speeds than Lightning and charges devices more quickly, which prompted Apple to start selling Lightning-to-USB-C adapters.
Apple had some financial incentive to retain Lightning: As a proprietary design, all Lightning accessories can only be produced by Apple or through a licensed partner. However, the broader compatibility and appeal of USB4 posed a competitive threat. Apple began phasing out Lightning in favor of USB4 across its product portfolio, with MacBook gaining USB ports in 2015 and iMac in 2021. The one holdout was the company's smartphone: the iPhone.
In 2023, Apple announced that it is also switching to USB-C for its future iPhone products, beginning with the iPhone 15. While this may have been a natural progression -- the iPhone was the only product still using Lightning -- the change was announced after the European Commission formally requested that all laptop and phone producers switch to USB-C connectors. Apple could have chosen to either leave the EU market or sell different, USB-C-compatible products in the EU alone, but it ultimately decided to make the switch on a global scale.
Madeleine Streets is senior content manager for custom content at TechTarget. She has also been published in Time, Women's Wear Daily, Self and Observer.