What is A USB Cable?

If you have a device with a USB port–such as a cell phone, PS4, VR headset, smart home devices, or laptop–you need a USB cable to charge it or transfer data with other devices. Unfortunately, when it comes to USB cable, there are many types of USB cables, even cables that look identical can behave very differently. Therefore, it is important to identify the device port and purchase a correct USB cable.

In order to better learn what a USB cable is, let us start with what is USB and what is USB port/connector.

What is USB?

USB, short for Universal Serial Bus, is an industry standard that establishes specifications for cables and connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. More about USB: Wiki-usb.

USB was originally developed by Intel, Compaq, Digital, IBM, Microsoft, NEC, and Nortel in 1994. After four versions (USB 1. x, USB 2.0, USB 3. x and USB 4), USB has now become Industry standards.

Usb 1.x

USB 1.0 was released in January 1996, and the specified data rate is 1.5 Mbit / s (low bandwidth or low speed) and 12 Mbit / s (full speed). USB 1.0 can be applied to the transfer rate of high-speed devices such as printers and floppy disk drives, as well as the transfer rate of low-data-rate devices of keyboards and mice. USB 1.1 was the earliest widely adopted version and led to what Microsoft designated the “Legacy-free PC”.

USB 2.0

USB 2.0 was released in April 2000. In addition to the USB 1.x full-speed signal rate of 12 Mbit/s, a higher data transfer rate was developed, so that the specification reached 480 Mbit/s, which was 40 times as fast as the original USB 1.1 specification.

USB 3.x

USB 3.0 was released on November 12, 2008. Its main goals were to increase data transmission rate, decrease power consumption, and increase output power. USB 3.0 adds SuperSpeed transmission mode, and is backward compatible with USB 2.0. SuperSpeed also provides a transmission mode at a rate of 5.0 Gbit/s. However, this rate depends on many factors, including physical symbol coding and link-level overhead, so it is difficult to reach 5.0 Gbit/s in actual use.

There are two versions of USB 3.1 released in July 2013. The first to retain the SuperSpeed transfer mode of USB 3.0 and label it as USB 3.1 Gen 1. The second version introduces a new SuperSpeed + transmission mode. SuperSpeed+ doubled the maximum data transfer rate to 10 Gbit/s, and was named USB 3.1 Gen 2.

USB 3.2 was released in September 2017, retaining the original USB 3.1 SuperSpeed and SuperSpeed+ data modes, but introduced two new SuperSpeed+ transmission modes through the USB-C connector, with data rates of 10 and 20 Gbit/s .

Starting from the USB 3.2 standard, USB-IF has introduced a new naming scheme to replace the original naming scheme, but in actual use, people generally call it usb 3.0, usb 3.1 and usb 3.2. In order to show the naming in more detail, please check the table:

Specification Name Previous name Data rate Transfer speed
USB 3.0 USB 3.2 Gen 1 USB 3.1 Gen 1 5 Gbit/s 500 MB/s
USB 3.1 USB 3.2 Gen 2 USB 3.1 Gen 2 10 Gbit/s 1.21 GB/s
USB 3.2 USB 3.2 Gen 2 × 2 N/A 20 Gbit/s 2.42 GB/s


USB 4 was released by the USB Implementers Forum on August 29, 2019. USB4 is based on the Thunderbolt 3 protocol specification. It supports a transmission speed of 40 Gbit/s, is compatible with Thunderbolt 3, and is backward compatible with USB 3.2 and USB 2.0.

Types of USB Connectors

USB connector (port) is different from the USB standard. usb is an industry standard and specification, and USB types(ports) refer to the interface type that uses the usb specification. For example, USB 2.0 refers to the industry specification, and USB type c refers to the usb interface type.

You can tell USB cables apart by the connector on either end. Here are the most common USB types.

USB Type A

USB type a is also called USB A, sometimes USB also refers to USB A. USB A connectors are flat and rectangular in shape. Type A is the “original” USB connector and is the most recognizable and commonly used connector.

USB Type-A port can be found in almost any laptop and computer. In addition, you can find USB A port on game consoles, home video receivers, and smart TVs.

Each version of the USB Specification(such as USB 2.0 and USB 3.0) supports USB A. USB 3.0 Type A connector is usually blue, but not always. USB 2.0 Type-A and USB 1.1 Type-A connectors are usually black, but not always black.

USB Type-B

USB Type-B cables is a connector with a square shape and a slanted outer corner at the top. Usually, USB Type-B cables are found on larger devices connected to the computer, such as printers and scanners. You may still find USB Type B ports on other devices, but this type of port has become very rare.


Mini-USB used to be a standard for various devices, but was soon replaced by Micro-USB connector mentioned below. You will find it on old models of various gadgets, especially cameras, MP3 players, and game controllers. As the name suggests, it is smaller than USB A, but larger than Micro-USB.

Mini USB cable is most commonly used to charge mobile devices, but can also be used to transfer data between computers with at least one USB port.

Micro USB

Micro USB is a miniaturized version of USB interface developed for connecting compact and mobile devices such as smartphones, Mp3 players, GPS devices, smart watch, cameras, Bluetooth speakers.

The design of the Micro USB port is poor. Incorrectly inserting the cable or accidentally applying pressure on the plug can easily damage it. So it is gradually being replaced by USB C.

USB Type C

USB Type C is usually called USB C, which is the most popular USB connector, used to transmit data and power to devices. The USB-C plug is symmetrical, so it can be inserted in any way, eliminating the troubles of early USB ports.

On many laptops and desktops, the USB-C specification also supports Intel’s Thunderbolt 3 data transfer technology. The USB-C port equipped with Thunderbolt 3 can push the data speed to the theoretical limit of 40Gbps.


Strictly speaking, Lightning is not a USB standard, but Apple’s proprietary connector for iPhone, iPad, AirPods, etc. It is similar in size to USB-C and has become a standard configuration on Apple devices since September 2012.

What is USB Cables?

Many electronic devices have built-in a USB port. Using a USB cable, you can connect the device to a computer or other device to charge or transfer data.

According to different USB standards (Specifications), USB ports are connected by cord to make USB cables. High-quality usb cable will also add a chip to the port, for example, Apple’s lightning cable has a c89 chip.

Most USB cables use a four-wire cable, two of which are used to transmit data, and the other two provide power to the device. In order to improve the transmission efficiency, some USB cables only have a data transmission function or a charging function.


USB Charging Cables

USB charging cable only has charging function. Quality charging cables have thick copper wire allowing up to 4X the amperage in charging vs the thinner wire in the cheap charging cables. If your phone ever gave you a slow charging message this is why. Some Cheap cables are 28AWG but if you want a better charging cable look for 24AWG.

Notice: The 24AWG is the charge wire and 24 is larger than 28.

Fast charging

Fast charging is a faster rate of charging than the standard rates. Fast charging cables send more current to your battery than regular cables. The regular USB cables send around 1A of current while fast charging cables deliver 5A(depends on your phone model and cable brand).

Fast charging cables are pretty thicker than regular cables because fast charging cables have thick wires inside. However, please note that if you pick thicker cable, it doesn’t mean it charges faster. Fast charging cable needs to be matched with a suitable chip to keep the current stable. And your device and charging adapter must also support fast charging.

Many devices that can be charged via USB connection do not contain any transferable data. For example, the light collar for the dog via mini fans. For such gadgets, pure charging cables are perfectly adequate.

USB Data Cables

USB data cable supports the transfer of data between different devices. Among the common USB cables, there are very few USB cables that only transmit data, but you can still find them on the mobile hard disk.

Different USB data cables have different transmission speeds, depending on which USB standard they use. For example, the transmission speed of USB 2.0 cable is 480/Mbps, and 3.0 is 5Gbps.

USB cable with different specifications is backward compatible and forward compatible, meaning it can support any USB version below or above its current number. For example, cables designed with USB 1.1 and 2.0 technology work in a 3.0 port. However, it should be noted that cable with lower versions run at their native transfer speeds even though USB 3.0 is capable of higher. Similarly, if you connect a USB 3.1 cable into a USB 2.0 port, the 3.1 cable’s max transfer rate is limited to that of the 2.0 port.

USB Charging&Datasync Cables

A Data sync and charging cable that allows for charging your device and data transfer from the computer.

The original USB cable is of this type. When you buy a smartphone from an authorized dealer, in the packaging you will find a USB cable. A USB cable does two things: it allows you to charge your moblie smartphone by plugging it into a USB port, but it also allows you to transfer data, such as pictures and music, between a computer and your cell phone.

USB Cable Types

From traditional USB to newfangled USB Type-C and Thunderbolt 3 ports, technological change is rapidly changing computers and mobile devices ports. Even if you’re familiar with the most common cell phone, it can still be a challenge to figure out what cables or adapters you need in order to plug your device into a computer or adapter. Bytecable wholesales the most common USB cables, and you can also customize USB cables.

USB Cables FAQ’s

Are USB cables all the same?

No. Even if two USB cables are identical in appearance, the internal settings may be different. For example, for the same USB C to USB A cable, USB 2.0 or 3.0 specifications can be used.

Can I use a USB cable to transfer files?

Like we mentioned at the beginning, not all USB cables can transfer files.

How can I tell the difference between USB 2.0 and 3.0 ports?

You can identify which USB specification your USB cables use by the color of the port.

  • USB 1.0 port features white plastic
  • USB 2.0 port features black plastic
  • USB 3.0 port features blue plastic

You can also check your device manual or consult the seller to get an accurate answer.

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