Universal Serial Bus (USB) was engineered for versatility. The iconic rectangular shape is familiar; we've all experienced the resistance a USB cable puts forth when forced into a machine upside down. Many of us have owned USB cords for years without considering their data transfer rates.

The rise of Apple devices brought with it a host of other cable shapes, use cases, and data transfer rates. The USB Implementers Forum (USB-IF) introduced the USB-C to universalize device connectors once again. USB-C's release coincided with Intel and Apple's release of Thunderbolt chargers, adding to the cable confusion.

Let's untangle this cord jargon.

What Is USB-C?

USB Type-C, or USB-C, as it's often referred to, merely refers to the shape of the connector itself.

For reference, the iconic rectangular-shaped USB cord is actually USB Type-A, less commonly referred to as the Standard-A connector. In this case, Type refers to the shape of the connector itself, whereas the USB version is expressed in numerical forms, such as USB 1.0 or USB 3.2, and dictates the performance of the technology within the cable. USB Type-A, USB Type-B, Mini-USB, and Micro-USB are some shapes that predate USB-C.

USB-C is smaller than its Types A and B predecessors, and the symmetrical oval shape makes plugging the cord in upside down a thing of the past. USB-C cords are available in all the latest USB standards, including USB 3.2 and USB4.

Today, the latest versions of popular laptops and tablets, including MacBooks and Chromebooks, feature USB-C charging ports. The next generation of consumers will find the oval shape as iconically familiar as the rectangular Type-A shape that Gen X and Millennials have come to know and love.

Pre-2011, the numerical USB standard dictated a cord's data transfer capabilities. But when Apple and Intel released the Thunderbolt technology, older USB standards could suddenly be supercharged.

What Is Thunderbolt?

Thunderbolt is a hardware interface designed to increase the data transfer rate significantly. When Apple and Intel first introduced Thunderbolt, it was exclusive to the MacBook Pro, but the advent of Thunderbolt 3 made the supercharged speeds available to any USB-C port.

Since the latest Thunderbolt versions both feature USB-C connectors, it's tempting to call them interchangeable. But just as a square is a rectangle but not vice versa, a Thunderbolt cable may have a USB-C connector but not all USB-Cs have Thunderbolt power.

Thunderbolt vs. USB-C: Speed and Shape

If USB-C's claim to fame is its versatile shape, Thunderbolt's key differentiator is speed. With a data transfer rate of up to 40Gb/s, Thunderbolt can effectively double the performance of a USB-C cord with USB 3.2 Gen 2.

The latest USB standard, USB4, harnesses the power of the Thunderbolt 3 protocol, which yields a 40Gb/s transfer speed for USB4 Type-C cables. And finally, the Thunderbolt 4 technology maintains its predecessor's 40Gb/s transfer rate and can also output video and charge compatible devices. Thunderbolt 4 supports up to two 4K displays or one 8K display and can be used for charging laptops requiring less than 100W of power.

See our guide to understanding Mac data transfer options for more information on supercharging your Mac's performance.

Thunderbolt vs. USB-C: Which One Should You Use?

The shape of the USB-C connector is quickly becoming ubiquitous in both Apple and PC laptops. The oval, symmetrical design makes it easy to connect on the first try every time—a stark contrast to its predecessor's rectangular Type-A connectors that required careful orientation for a successful connection.

In terms of data transfer capabilities, your choice depends on the devices you own. For example, if your computer was released after 2016, look for a lightning symbol next to one or more of the charging ports. If you see the lightning, you have a Thunderbolt 3-enabled device on your hands; any cord with a USB4 or Thunderbolt label should offer similar performance results when connected to another Thunderbolt 3 device. On the other hand, if you own an older computer that lacks the lightning bolt symbol, a Thunderbolt 2 or USB 3.0 cord should suffice for your needs.

The latest generations of Apple and Intel-powered laptops feature at least one Thunderbolt 4 port—enabling data transfer rates of up to 40Gb/s as well as video output and power charging capabilities in select models (no such luck for AMD hardware as yet, though). If you own multiple devices compatible with different versions of Thunderbolt technology, consider investing in a multi-port adapter, such as the Accell Thunderbolt 4 Docking Station, so you can connect everything at once without purchasing several adapters for every device.

As more devices move away from proprietary charging ports (such as those found on older MacBook models), you can expect to see an influx of products compatible with USB-C cords only. While some manufacturers may still include standard Type-A or even Micro-USB cables as accessories, these connector types will eventually be phased out in favor of their smaller sibling, USB-C.

What Will They Come Out With Next?

We can only speculate what the next version of Thunderbolt or USB will bring. But for now, we know if you need to transfer large amounts of data quickly, a Thunderbolt-powered cable of USB-C type is your best bet. And as more devices adopt the USB-C connector shape, future versions of these technologies will likely be compatible, making our lives just a little bit easier in the process.