||Standard USB Type-A
The USB Standard-A type of USB plug is a flattened rectangle which inserts into a “downstream-port” receptacle on the USB host, or a hub, and carries both power and data. This plug is frequently seen on cables that are permanently attached to a device, such as one connecting a keyboard or mouse to the computer via usb connection.
Standard USB Type-B
A USB Standard-B plug which has a square shape with bevelled exterior corners—typically plugs into an “upstream receptacle” on a device that uses a removable cable, e.g. a printer. A Type B plug delivers power in addition to carrying data. On some devices, the Type B receptacle has no data connections, being used solely for accepting power from the upstream device.
USB Mini-B 5 pin
The USB 5-pin Mini-b is the most popular style of Mini-b connector, and the only one recognized by the USB-IF. By default, a Mini-b cable is presumed to have 5 pins. This connector is quite small, about two-thirds the width of an A-style connector. It is also specified for use in the newer standard called USB On-The-Go which allows peripheral devices to communicate with the presence of a host controller.
USB Mini-B 4 pin
The USB Mini-b 4 pin connector is found on many digital cameras and mobile phones which resembles the shape of a standard b-style connector but much smaller in size.
Micro USB A-B
Micro USB A-B is exclusively for USB On-The-Go devices, this versatile connector can accept either a Micro-USB A or Micro-USB B cable connection. This interface can be easily identified by its gray-colored receptacle and compact 5 pin design. This connector type only exists as a receptacle for On-The-Go devices and will not exist on a cable.
Revolution of USB Connections
USB was developed in the effort to simplify the connecttions between computers and peripheral devices and became widely popular due to its compatibility with many platforms and operating systems.
USB 1.0 which was released in 1996 had a specified data rate of 1.5 Mbit/s (Low- Bandwidth) and didnt allow for extension cables or pass through cables due to power and timing limitations. Only a few USB 1.0 devices actually made it to the market before the release of USB 1.1 which fixed problems identified in version 1.0 and became widely adopted.
In the year 2000 USB 2.0 was released which added higher maximum bandwidth of 480 Mbit/s (60 MB/s) and was now called “High Speed”. Engineering modifications to the USB specs have been done by the ECN’s and is available at ConnectZone.
USB 3.0 which is the most reccent transition and updated specifications of USB connections was released in the year 2010 as a consumer product. This opened hardware developers to for implementing future products.