The most streamlined and common USB types you will see is Type A and Type C.
Type A
Standard USB
These are 4-pin USBs.
3.0 Variants
Further variants of Type A and Type B occur as a direct result of USB 3.0’s power requirement. These require 9-pins, though they look and function the exact same as the 4-pin variants.
Type C
Standard
Uses 24-pins AND can be inserted in either orientation. It also supports Thunderbolt. Can support speeds of 10 Gbps