The USB standard specifies tolerances for impedance and relatively low mechanical specifications for connections, trying to minimize the incompatibility between the connectors manufactured by different companies, a goal that has been reached. The USB standard, unlike other standards also define sizes for the area around the connector on a device, to avoid blocking adjacent ports on the device.
USB specifications 1.0, 1.1 and 2.0 define two types of connectors for connecting to server A and B. However, the layer has changed in some mechanical connectors. For example, IBM Ultraportable is a private USB connector located on the top of the LCD of laptop computers from IBM. Uses a different mechanical connector while maintaining the characteristic signs and USB protocols. Other manufacturers of small items have also developed their means of connecting small, and has appeared a variety of them, some of poor quality.
An extension of USB called USB-On-The-Go "(on the go) allows one port to act as a server or device - this is determined by which side of the cable is connected to the device. Even after the cable is connected and the units are communicating, the 2 units can "change paper" under the control of a program. This facility is specifically designed for devices such as PDAs where the USB link might connect to a PC as a device and a server to connect a keyboard or mouse. The USB-On-The-Go "has also designed 2 small connectors, the mini-mini-A and B, so this should stop the proliferation of miniature connector input.
Pendrive
A USB (Universal Serial Bus, in English pendrive or USB flash drive) is a small storage device that uses flash memory to store information that may or not require batteries (batteries), the latest models in the battery is not required The battery was first used by the models. These memories are resistant to scratches (external) to dust-and water-some that have affected the forms prior portable storage such as floppy disks, CDs and DVDs.
Current operating systems can read and write the reports by simply plugged into a USB connector on the computer on, receiving power supply through this connector. In some older computers (eg Windows 95) will need to install a device driver (driver) provided by the manufacturer. GNU / Linux systems also have support for USB storage devices.