Computer cables (data cables) are somewhat similar to audio and video cables. Instead of transmitting sound or images, they send data for your computer to use. This can be anything from sending over a Word document to streaming movies and TV shows. Technically ethernet cables fall under this category, but ethernet is such a broad topic it needed its own independent article. Common types of data cables include:

  • USB
  • FireWire
  • Serial
  • DIN
  • PS/2

USB

USB is the most common type of data cable today, being found on computers, printers, hard drives, cell phones, and more. Along with transmitting data, USB is commonly used to recharge batteries on cell phones and other devices like video game controllers. There are several types of USB cables in various shapes and sizes. The two primary groups are USB 2.0 and USB 3.0.

USB 2.0 is capable of speeds up to 480 Mbps and comes in a few different varieties. When someone just says “USB”, they are generally referring to USB 2.0 Type A. These are the standard rectangle-shaped connections you can find on any computer. Next, there is Type B, which is also called a printer cable. Newer printers use this more square-shaped connection instead of older serial connections. Mini USB used to be used on cell phones but has mostly been replaced by Micro USB. You will still occasionally see it on other devices like digital cameras and GPS. Micro USB is still the standard on many Android phones but is starting to be replaced by USB 3.0 Type-C.

Another version called a Lightning cable also exists. This type of cable is proprietary property owned by Apple and used exclusively for iPhones. While Lightning connectors are a different shape from other types of USB, it is functionally the same as a Micro USB cable on an Android phone and is used for moving data and recharging batteries on iPhones.

USB 3.0 is capable of speeds up to 5 Gbps and also comes in different varieties, which share a lot of the same names with their 2.0 counterparts. However, except for USB 3.0 Type A, they are all different sizes and shapes. Keep this in mind when purchasing cables to make sure everything can fit together. USB 3.0 Type A is the same size and shape as 2.0 but colored blue instead of black so users can tell them apart. A 3.0 cable is backwards compatible with 2.0, but you will only get 2.0 speeds if using it that way. Using 3.0 and 2.0 together will also only recharge a cell phone or other battery at the 2.0 level.

All other types of USB 3.0 are different shapes than the 2.0 versions and are not interchangeable. USB 3.0 Type B looks very similar to the 2.0 version, but the shape is slightly different and prevents the 2.0 and 3.0 from fitting together. USB 3.0 Micro is bigger than the 2.0 version and commonly seen on newer external hard drives. While USB 3.0 has not been widely implemented yet, the industry is slowly transitioning there as 2.0 equipped devices get older and begin to die off.

There is also a USB 3.1, more commonly called USB-C (or Type-C), that can handle speeds up to 10 Gbps and recharges devices even faster than 3.0. Type-C is starting to see implementation onto the newest cell phones, replacing the old USB 2.0 Micro connections. While the two look somewhat similar, Type-C can be identified from its round oval shape that lacks the pointed edges of a 2.0 Micro connector. Designed as a one-size-fits-all type of connector, the goal of the industry is to have Type-C replace all other USB cables in the near future to eliminate the need for all these different types of cables.

USB 2.0
USB 3.0
USB A
USB B
Mini
Micro
USB 3.1
Type-C


Top: USB 2.0 A (left), B (center-left), Mini (center-right), and Micro (right)

Bottom: USB 3.0 A (left), B (center-left), Micro (center-right), and Type-C (right)

FireWire

FireWire (also called IEEE 1394) is an older type of data cable originally developed by Apple for Mac computers. While not as common as some other types of computer cables, it still sees some use today on devices like camcorders and some external hard drives. FireWire is not a bad type of cable it has frequently been the underdog and never fully managed to get ahead of USB.

There are two different classifications of FireWire. FireWire 400 comes in 4-pin and 6-pin variants while FireWire 800 has 4-pin, 6-pin, and 9-pin versions. FireWire 400 is the original version of the cable and named after its 400 Mbps (Megabyte per second) transfer speed. FireWire 800 is version two, doubling the speed of the original cable. While FireWire 800 was significantly better than its competitors for a while, said competitors have continued to make improvements while FireWire holds the same standard it has kept for years.

If you have the option of USB 2.0 and FireWire, FireWire will be the better option. However, the newer USB 3.0 and even newer USB-C are both superior to FireWire 800. As those newer USB options become more mainstream, FireWire may become obsolete.


FireWire 400 4-pin, FireWire 400 4 pin
FireWire 400 6-pin, FireWire 400 6 pin
FireWire 800 4-pin, FireWire 800 4 pin
FireWire 800 6-pin, FireWire 800 6 pin
FireWire 800 9-pin, FireWire 800 9 pin
FireWire 4-pin, FireWire 4 pin
FireWire 6-pin, FireWire 6 pin
FireWire 9-pin, FireWire 9 pin

FireWire 4-pin (left), 6-pin (middle), and 9-pin (right)

Note: 4-pin and 6-pin connectors look the same on FireWire 400 and 800

Serial

Serial cables are also called DB or D-Sub (D-Subminiature) cables, designated “DB#” with the number standing for how many pins are in the connector. In general, serial cables are outdated and have largely been replaced by newer types of connections like USB and FireWire. There are computers, monitors, and other equipment that use serial connections still functioning, but you will not see these on many brand-new machines as serial cables edge closer to becoming obsolete.

There are a few different kinds of serial cable, the first being DB9. DB9 was commonly used for monitors before it was replaced by VGA (which itself is now on its way out) and for devices like mice and keyboards which were replaced by PS/2 and later USB. DB9 is also called RS232 and looks similar to VGA, but with two rows of pins instead of three. DB15 used to be found on sound cards and old Mac monitors and also resembles VGA, but like DB9 it uses two rows of pins instead of three. DB25, also called a parallel port, was common on printers before USB 2.0 B replaced it. DB37 was used with old Cisco hardware. Serial cables are sometimes called Cisco cables since they were used so heavily with Cisco equipment back in their prime.

Serial cable
DB, DB9, DB15, DB25, DB37
D-Sub
RS232, RS-232

Top: DB9 (left) and DB15 (right)

Bottom: DB25 (left) and DB37 (right)

DIN

DIN stands for Deutsches Institut für Normung (German Institute for Standardization) and comes in a multitude of configurations. DIN connections are referred to by their number of pins (3-pin DIN, 4-pin DIN, etc.). Some pin numbers will also have various configurations, which are in turn referred to by the degree angle of the pin layout. For example, 8-pin DIN comes in 262° and 270° versions. There are also Mini versions of some DIN connectors, but these are generally developed for specific uses and referred to by other names. For example, an S-video connection is actually a 4-pin Mini DIN but is generally just called S-video. DIN connectors can be used for many applications including power, audio, and data transmission, to name a few.

DIN cable connector
3-pin, 4-pin, 5-pin, 6-pin, 7-pin, 8-pin
degree
180, 216, 240, 262, 270

Note: This image does not display all available DINs, but these are the most common types.

PS/2

PS/2 is a type of Mini-DIN connection formerly used for computer keyboards and mice. There are two different versions, purple and green, with purple being for the keyboard and green being for the mouse. They may look the same but the two are not interchangeable. A keyboard plugged into a green PS/2 will not work and vice versa for a mouse and purple PS/2. Keyboards and mice with PS/2 connections can still be found used, but have largely been replaced by USB.