USB interface standards include USB type-a and USB type-c, which are the most common. Type-a is currently the most classic USB interface and can be seen in various computers, USB drives, and other devices.

Many people have not seen the USB type-b native interface, and the application scenario is very small, mainly visible on some large output devices such as printers. However, we have seen a lot of USB type-b branch standard Micro B in previous Android phones, such as the Samsung S5 that I have used before, which uses Micro B as the charging port.

Finally, Micro B comes with USB type-c, which is a new interface standard that has been widely used in recent years. Currently, most mainstream Android phones use USB type-c, also known as USB C port, with the feature of being able to plug in both front and back.

USB protocol: After discussing the interface standards, let's take a look at the USB protocol again. Why can the same USB type-a interface transfer a file in a few seconds, while others take a few minutes? This is the impact of interface protocols.

At present, there are four main USB interface protocols, namely USB 2.0, USB 3.2 Gen 1, USB 3.2 Gen 2, and USB 3.2 Gen 2x2. These protocols have different speeds, with the fastest being USB 3.2 Gen 2x2, and the most common and slowest being USB 2.0. The specific speeds are shown below.

USB 2.0=480Mbps

USB 3.2 Gen 1=USB 3.0=5Gbps

USB 3.2 Gen 2=USB 3.1=10Gbps

USB 3.2 Gen 2x2=USB 3.2=20Gbps

These interface protocols, combined with interface standards, will form a complete USB interface. The USB type-a can be USB 2.0, USB 3.2 Gen 1 protocol, or USB 3.2 Gen 2. However, USB 3.2 Gen 2x2 only adopts the type-c standard and does not have the USB type-a standard.

If DC's biggest rival is Warner, USB's biggest rival is USB-IF. Because the USB-IF alliance that formulates the USB interface protocol is really too busy, it will change the name of USB when it is idle. It will change the easy to remember USB 3.0, USB 3.1 and other interfaces into USB 3.2 Gen 1, USB 3.2 Gen 2. This will give a lot of people a big surprise. Who will have nothing to remember such a complex name?

Thunderbolt Protocol: After discussing the USB protocol, let's finally talk about Thunderbolt Protocol. Everyone is familiar with the Thunderbolt 3/4 interface. These interfaces use the Thunderbolt protocol, which is different from the USB protocol. The Thunderbolt protocol is not customized by USB-IF, but developed by Intel. It is currently available for free and has a faster transmission rate of up to 40Gbps.

However, in terms of interface standards, Intel did not come up with a new version, but instead used type-c to be compatible with the Thunderbolt 3/4 interface. Therefore, Thunderbolt 3/4 can be a type-c interface, but it cannot be reversed that type-c is all Thunderbolt 3/4 protocols because type-c can also use USB 3.2 Gen 2x2 and USB 3.2 Gen 2.

The lightning interface 3/4 interface is now quite sophisticated, and a small lightning symbol is printed next to the interface. As long as you see the type-c interface with a lightning symbol, it indicates that this interface is a lightning interface.

Source: Zhongguancun Online