USB, short for Universal Serial Bus, is a common type of computer port that makes it easy to charge a device or transfer data between two devices. Since it was first developed in the 90̵7;s, USB has continued to evolve with the technology and has gradually become smaller, faster and more powerful. With so many devices using USB, it is easy to get confused by the various connectors. But do not be afraid – we will demystify all this today.
When it comes to USB, there are really only four things that matter: form factor, transfer speeds, power supply and video delivery. Let’s dig in.
There are several types of USB that have emerged over the years, each with a unique design and use case. The most common types are USB-A, Micro-USB and USB-C, but we will briefly discuss them all.
USB-A, or USB type A, is the original flat and rectangular connector that no one could ever figure out how to connect properly the first time. These cables always have USB-A at one end with a different port type at the other and can be used for device charging and data transfer. USB-A is still widely used and is found on devices such as computers, game consoles, TVs and all types of peripherals.
USB-B is largely used only on large devices, such as scanners or printers. Visually, this contact looks almost square. Most of these are USB-B to USB-A cables, although some newer devices have gone from USB-B to smaller options, such as Micro-USB or Mini-USB.
Micro-USB was standard a while ago for some portable devices, such as Android tablets and smartphones, as it can transfer data and charge. It is available in both Type-A Micro and Type-B Micro flavors and is smaller than USB-A. Some manufacturers still choose to use Micro-USB parts for their devices, as they are cheaper than those for USB-C.
As the name suggests, Mini-USB is a smaller version of USB-B. It was the standard for charging or transferring data from devices such as tablets before Micro-USB was. There are also versions of Type-A and Type-B of this connector. It is unusual to see many products using Mini-USB today, but you can still find them on older electronics such as MP3 players or the PlayStation 3 controller.
This is the current standard, and it marries power and data delivery with screen connection. USB-C is what you see on most new devices such as smartphones, game controllers, earphone cases, microphones and laptops. Its form factor is small, oblong and reversible, so it can be connected in any way (take it, USB-A). The port’s 100-watt connection makes it perfectly suited for fast charging and data transfer, even with larger devices.
USB-C can do more than other types of USB and get it done faster. USB-C has the potential to replace all other cables, thanks to its various multitasking features. It has the ability to power even the most power-hungry devices, such as laptops and TVs. It can also transmit 40 gigabits of data per second (Gbps) and can be used to deliver 4K video to external monitors.
While manufacturers continue to release new products with ports other than USB-C (look at you, Apple), we can not yet live in a single cable community, but we will get there and we may eventually be relieved of the burden of dragging around multiple cables .
Technically, Lightning is not USB but rather Apple’s proprietary connection type that works in the same way as USB. You see it on Apple devices, like the iPad and iPhone. It is similar to USB-C in that it is reversible. It supports speeds similar to USB 3.0.
Data transfer rate
In addition to the different shapes and sizes, USB types also have several speed standards. Keep in mind that some USB cables are only data transfer and others only electricity supply, but also that there are options that can handle both tasks. Be sure to verify the capability of a cable before purchasing it.
The first, USB 1.x, is old and incredibly slow and can only move 1.5 Mbps. Your odds of finding a device in nature still at 1.0 are small to none. The slightly less old (and conveniently slow) USB 2.0 is still relatively common, but you can only find it on older electronics. 2.0 has a full speed option that can handle 12 Mbps, and a high speed version that can handle 480 Mbps. SuperSpeed USB 3.x can transfer data between 5-20 Gbps.
The latest entries, USB 4.0, Thunderbolt 3 and Thunderbolt 4, are where you will find the highest data transfer speeds: a maximum capacity of 40 Gbps. Thunderbolt is another transfer rate standard used in some USB-C cables – all Thunderbolt 3 and 4 cables are USB-C, but not all USB-C cables are Thunderbolt. So if Thunderbolt is what you are looking for then you need to make sure it is part of the cable you are buying.
These super-high transfer speeds are impressive, but they do not matter if you do not regularly transfer hundreds of GB of data or do something wild like editing video on an external hard drive. If you are, however, you want at least Thunderbolt 3.
As we mentioned above, some USB cables can only supply power or transmit data, although most can do both. PD standards (power supply) fall into one of three main categories: power only, slow charge and fast charge.
USB 2.0 supports 2.5 W charging and USB 3.0 supports 4.5 W charging. To put things in perspective, 10W is enough power to charge your phone slowly and 18W is enough to quickly charge your smartphone or power a Netbook or similar laptops.
However, the USB PD can handle up to 100 W, which is powerful enough to power things like a MacBook Pro, monitors, docking stations and most TVs. It can also quickly charge smaller compatible devices like your phone or Nintendo Switch. PD also provides only the necessary charge to your device but does not charge too much. Newer battery banks are starting to support USB PDs, which are more capable of keeping your energy-intensive devices powered and fully charged.
To be able to transfer data and running a device is already impressive. But you can also choose to use USB-C to connect to monitors instead of a bulky HDMI or VGA cable. USB-C also supports 4K video delivery to a monitor. Thunderbolt 4 cables can handle the display of 4K content on two monitors at a time, or 8K on a single monitor. Again, this will not be the case for most people, but as 4K and 8K video become more common, you will eventually need a cable that can keep pace.
How to know if you are using a secure USB cable
The rule of thumb is that you should always use the cable that came with your device and that you should also buy some replacements from the manufacturer. That cable is specially designed for use with your phone, tablet or computer.
But if you want to buy one from a third party, be sure to stick to reputable established brands like Anker, Aukey or Belkin, or at least see if another brand lists the cable’s USB certification. Otherwise, you could end up with an inferior cable that lacks official USB-IF certification and could potentially damage your device.