The very name Universal Serial Bus (USB) is an ambitious promise: one port to rule them all. Unfortunately, the reality is more complicated than that. These days, your phone, tablet, and laptop may all use the same USB-C port for charging and data transfer, but they all work differently.
What is USB4? What is Thunderbolt? Is it the same as USB-C? We’ll answer all these questions and help you get the best performance from your devices.
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USB Glossary
First, it’s important to define some terms up front.
USB 2.X/USB 3.X/USB4
All USB devices are built on a version of the USB specification, which is maintained by the USB Implementer’s Forum (USB-IF). These versions are characterized primarily by the amount of data they can transfer and the amount of power they can supply (at least, these are the main considerations). Most of these devices are interoperable as long as they use the same type of port, but the entire chain will conform to the slowest part of the chain. For example, if you connect a USB 3.2 solid-state drive to a USB 3.2 port on your computer and use a USB 3.0 cable, data will only be transferred at USB 3.0 speeds. Make sure all links in the chain support the speed you need.
USB Power Delivery (or USB-PD)
Instead of carrying a charger for each device you own, you can choose a charging adapter that can charge multiple devices through multiple USB-C Power Delivery (USB-C PD) ports. Power Delivery is a fast charging method that supports up to 240 watts of power, allowing your gadgets to securely communicate with the charger to sort out their power needs appropriately. USB hubs also have such ports, and they’re sometimes called “pass-through charging,” although this is not the official term.
Make sure the wattage of the USB-C port on your charging adapter or hub can handle the needs of your device. A MacBook Pro typically requires 96 watts under heavy load (though it can charge at lower wattages), so for the best charging experience you’ll probably want a 100-watt USB-C port on your charging adapter or USB hub.
USB-C vs. USB-A
These terms refer to the physical shape of the connector and port on your device. USB-C is the common one, a small, elongated oval. It’s also reversible so you can’t plug it in the wrong way. USB-A is the old rectangular port that’s been around for years. There are many other types of USB connectors, but these are the two you’ll most commonly see today on charging adapters, hubs, and docking stations.
Super Speed
You may also see some USB devices marketed with terms like “SuperSpeed,” “SuperSpeedPlus,” or “SuperSpeed USB 5/10/20 Gbps.” These terms were originally intended as more convenient, marketable labels to indicate the generation or speed of a USB port, but unfortunately, they only led to confusion. For the most part, you should ignore these labels and check the actual speed rating.
What’s happening with USB generations?
It would be nice if you could just use a USB 3.2 cable to connect a USB 3.2 device to a USB 3.2 port and be assured that everything would work just fine, but unfortunately, the reality is a lot more complicated than that.
When USB 3.0 was introduced in 2008, it had a maximum speed of about 5 gigabits per second (Gbps), but when USB 3.1 was introduced in 2013 with a maximum speed of 10 Gbps, the 5 Gbps version was renamed to USB 3.1. 1st generation, The new high-speed specification was USB 3.1 Second GenerationConfused? Well, it gets even worse.
After the introduction of USB 3.2 in 2019, 5Gbps USB was rebranded. Also It was “USB 3.2 Gen 1”, the 10 Gbps version became “USB 3.2 Gen 2”, and the new 20 Gbps spec is now, you guessed it, USB 3.2 Gen 2×2. Huh? What? “2×2” means it runs two 10 Gbps data lanes at the same time. You don’t need to know all that stuff. Many USB hub and docking station manufacturers have given up on using names, labels, and symbols. They now just print the maximum speed directly next to the port.
