Ports are more confusing than they should be. With all the different USB standards out there, it’s easy to get overwhelmed by the number of options. USB-A and USB-C are the two most common forms of USB, and knowing the differences between the two is essential for understanding what all your devices and peripherals can do.
What is USB-A?
USB Type A connections refer to the physical design of the USB port. Every USB connection is made of a port in the host device, a connecting cable, and a receptor device. USB-A is a traditional USB host port design and one of the easiest to recognize on devices.
It’s a horizontal port with the bottom portion dedicated to pin connectors. This arrangement creates the infamous one-sided USB connection that only works when the cable is inserted correctly, no matter how many times you have to try.
Interestingly, there is no USB-B host port. The USB-B design is the receptor port located on the device you are connecting to the host computer. Type B connections are also easy to recognize because they are squared with rounded corners on one side, almost like the shape of a little house. USB-B is mainly used for external peripherals, with a USB-A connection on one end and a USB-B connection. There are USB-B to USB-B cables, but they’re rarely used.
Note that there are also subsets of this design, like USB Mini A and USB Micro A, with different port designs, but these aren’t as important for our current discussion.
What is USB-C and how does it differ?
USB-C is a newer port design officially announced in 2014, although it took several years for the ports to reach widespread consumer devices, as we see today. USB-C was made to be an entirely new type of USB port that would solve many of the problems of the old USB-A port. Critical features of USB-C include:
- A slimmer design that can fit into a port no matter which direction it’s flipped, designed to replace A, B, mini, and micro connections all at once.
- A 100-watt, 20-volt connection that’s far more powerful than the older port and can handily power even larger devices.
- Potential for much higher transfer speeds than USB-A.
- Support for power delivery so that it can charge up devices located on either end (with the right cables) and charge larger devices.
- Support for video delivery at much higher quality, including the ability to transmit 4K video to a screen.
- Support for alternate modes that allow for lots of different adapters for specific connections like HDMI or VG — or older types of USB connections.
- Potential compatibility with Thunderbolt 3 connections, which means a USB-C port can double as a Thunderbolt 3 port with extra hardware.
So, USB-C is a better connection?
With the right data standard (see below), USB-C is much faster and more versatile than USB-A. In time, you can expect USB-C connections to replace all older USB-A connections and other ports. This switchover will, however, probably take years.
For now, USB-A tends to show up alongside USB-C in many computers, primarily due to compatibility issues. People still have older smartphones, beloved controllers, receivers, TVs, keyboards, and all manner of peripherals that require a USB-A/B connection.
Most people don’t want to buy an adapter to make USB-C backward-compatible with all their stuff. As the use of these older devices fades, USB-C will become the go-to port that everyone knows to look for — and we already see this happening in some sectors.
Where does USB 3.1 fit into this?
USB 3.0 or 3.1 refers to specific data protocols for USB connections: Instead of describing the physical port, this refers to what kind of data the port can handle. A notable change came with USB 3.0, which required a modification of the USB-A and USB-B designs to acquire more capabilities and faster speeds. USB-A cables that support USB 3.0 and above are usually noted with a blue pin protector instead of the standard gray one.
USB 3.1 is typically divided into USB 3.1 Gen 1 and USB 3.1 Gen 2 and offers many of the data improvements that USB-C supports, including speeds up to 10Gbps and new charging capabilities.
To make matters more confusing, USB-A and USB-C ports can support a variety of standards, anywhere from USB 2.0 to USB 3.1 Gen 2. Even worse, not everyone uses the same names for these protocols, so USB 3.1 Gen 1 is sometimes called USB 3.0. The goods news is that USB 3.1 is backward-compatible with all other USB connections, although an adapter may be required for USB-C ports. You’ll also need to make sure that your USB cables and devices support 3.1 data capabilities when possible.
Have a headache yet? Let’s simplify things with a few crucial points to remember:
- USB-A and USB-C can have various data standards, up to USB 3.1, which dictates their data capabilities.
- USB 3.1 is backward-compatible with other standards, although adapters may be required, making it a good standard to look for.
- Only a USB-C connection can utilize the full potential of USB 3.1 Gen 2.
- Cables and devices must also support the USB data standard — if you get a port with USB 3.1, your cable and your connected device must also support 3.1 to take full advantage of it.
- Buckle up: USB 3.2 standards are already well on their way and will make things even more confusing, with several varieties and each with their own name.