The Universal Serial Bus (USB) is a standard that is nowadays used to connect all types of devices. Although the name says “universal” this is misleading as there are a few different standards and many different USB connector types.
In this article, we’ll discuss the various USB iterations so you’ll understand which type of connections to expect with which devices. We’ll also show you images to make identification much easier.
Types of USB Connectors
USB cables differences can be identified by looking at the connectors on either end. The most common types are discussed below.
This standard connector can be found on one end of just about every USB cable. The connector is rectangular and it can only fit into a port one way.
There are a number of USB-A ports on just about any laptop and desktop computer, as well as on many game systems, TVs, media players, cars, and other devices.
There aren’t any cables that have a USB-A on both ends, as there’s not a situation in which this could be used. Connecting two computers with a USB-A cable could in fact cause damage to them both.
This older type of connector is not used often anymore. The one end is almost square and it is usually plugged into devices like printers. Other than this use, it’s largely been superseded by newer standards.
This smaller connection type is good to use with mobile devices. Although it’s been largely replaced by micro-USB, you’ll still see it on some MP3 players, cameras, and other devices like that.
This tiny connector is very popular on a wide range of portable devices. Everything from Bluetooth headphones to external battery packs to Android phones uses micro-USB ports. Some smartphones have however already started using the newer USB-C port.
This is the latest USB standard. While older cables usually have USB-A on one end of the cable and another type on the other, a USB type C connector can be used to connect two devices that both have USB-C ports. It is also reversible, unlike the other types above.
Device manufacturers are slowly adopting USB-C. Many newer Android phones, such as the Samsung Galaxy S9, Google Pixel devices, as well as Apple’s newest MacBook Pro and MacBook models use USB-C ports.
If you have heard about USB-C, you may also know about the Thunderbolt hardware interface. This standard allows a USB-C port and cable to connect to high-resolution displays, transfer data at very fast rates, and perform other functions.
Thunderbolt 3 is however not supported by every USB-C port. Apple’s newest MacBook Pro models for example come with several Thunderbolt 3 USB-C ports, although the standard MacBook’s single USB-C port does not support Thunderbolt 3.
All of this can make USB-C confusing. The port can either be a multi-purpose jack, or it can be a basic USB port similar to the ones described above. This will largely depend on the device. For more information about USB C, check out the reasons Cable Matters gives why USB-C docking stations are so useful.
Although this is not strictly speaking a USB standard, we have included it for completion’s sake. Since late 2012, Apple has used this proprietary cable in its mobile devices. It is reversible, like USB-C.
iPad and iPhone users use a USB-A to Lightning cable to charge their devices, connect to a PC, and more.
USB Speed Standards
USB has updated the standards several times throughout its life. Apart from the types of connectors used, each USB port and cable adheres to a speed standard.
Although USB 1.0 was originally released in 1996, it wasn’t until 1998 that USB 1.1 was released and started the USB era properly. This standard only catered for USB-A and USB-B connectors and is antique by modern standards.
You will not likely find any USB 1.x cables or devices around today.
With its 2.0 update in 2000, USB got a major revamp. This version supports much higher speeds than version 1 did, while also introducing support for several of the newer ports mentioned before.
It also made a notable improvement by adding support for USB OTG (On-The-Go), which enables two USB devices to communicate with each other directly. You can for example connect a standard USB keyboard to an Android phone with an adapter.
USB 2.0 is still being used in cheap flash drives, together with many keyboards, mice, and similar devices. If a port or cable doesn’t have markings that show that it is USB 3 as discussed below, it’s likely still the older USB 2.0.
USB 3.0 was launched back in 2008 and was later followed by the 3.1 and 3.2 iterations. Its biggest improvement was that it offers transfer speeds that are much faster than USB 2.0 what provides.
USB 3.x ports and cables can be recognized by their lightning bolt logo and/or blue color. As these devices have been designed to be backward-compatible, you can plug a USB 2.0 cable into a USB 3.x port or vice-versa. This will however limit the connection to USB 2.0 speeds.
Many higher-end flash drives and external hard drives use USB 3. USB-C cables are always USB 3. Older cable types, such as micro-USB, need a special type of connector to be compatible with USB 3.0. This type of connector is often seen on external hard drives so they can utilize USB 3 speeds.
Now you know the different types of USB cables and what they are used for. You can normally plug standard devices such as keyboards and mice into USB 2.0 ports, as speed is not important for them. Any device that is used to transfer data, such as external hard drives, should however be plugged into USB 3 ports to get the best results.
Only time will tell if USB-C becomes the go-to standard and if it will eventually replace the others or not. We will however likely still be able to get USB-A ports for a long time so that older devices can be supported.