What is the importance of RS232-C in serial communication?
RS-232 that is Recommend Standard number 232 and C is the new revision of the standard. The serial ports on main computers utilize a subset of the RS-232C standard. The full RS-232C standard gives a 25-pin "D" connector of that 22 pins are used. Many of these pins are not required for normal PC communications, and indeed, latest PCs are equipped with male D type connectors having just 9 pins.