Micro USB is a portable version of USB 2.0 standard, smaller than the mobile phone using the Mini USB interface, is the next generation USB Mini .
Micro -USB supports OTG, like Mini - USB , also 5 pin.The definition ofMicro series including standard equipment using Micro - B series slot.
OTG (On-the-go) devices use Micro - AB slots with Micro-A and Micro-B plugs and cables. Micro series use stainless steel shells, which greatly increases longevity.