Service mark symbol. The service mark symbol (â ), the letters SM in superscript style) is a symbol used in the United States to provide notice that the preceding mark is a service mark.
Size matters: The micro and mini USB connectors are of similar width. But the micro connector is much thinner (smaller vertical dimension). Some product designs were not able to accommodate the height of the mini receptacle and the new thinner receptacle will encourage and allow thinner products.
USB 2.0 is a version of the USB standard, and probably the most widely available one. USB 1 is old and never really caught on. USB 3 is new, very high performance, and is only just becoming widely available. It is 10 (USB 3.0) or 20 (USB 3.1) times faster than USB 2. USB Type C is new connector for USB. Traditionally USB used a Type A connector on the Host (computer) and a Type B connector on the peripheral (phone etc), There were several variants of the Type B, of which the most familiar is the Type B micro used on most mobile phones. Both Type A and Type B had variants to carry the extra conductors for USB 3.