Most of the material have been referred from wiki USB - Wikipedia
Universal Serial Bus (USB) is an industry standard developed in the mid-1990s that defines the cables, connectors and communications protocols used in a bus for connection, communication, and power supply between computers and electronic devices. Data as well as power is transmitted using the same cable.
USB Plug (Male Connector)
USB cables will only have plugs.
USB Receptable (Female Connector)
Host devices will have the receptables.
Physical compatibility between plugs and receptables
Cable plugs (USB 1.x/2.0)
USB cables exist with various combinations of plugs on each end of the cable, as displayed below. Notes from the section above apply here as well.