Arduino USB | SERIAL to PC communication

How to connect arduino mini to PC using PC's serial port? I have an atmega328 based arduino mini.It doesnt has a usb chip.I googled and found that normally it needs a FTDI cable to communicate with PC.But PC already has a serial port so can't I just connect the arduino directly through that port?? If so how should I do that please explain and Im new to arduino.

The Arduino sends serial at TTL levels in "true" format (polarity), whereas the PC serial port expects "inverted" serial at RS232 levels. (+12V/-12V) Edit: Actually, I think the standard stipulates +3V to +25V/-3V to -25V, but PCs usually use about +12V/-12V.

You'd need a TTL to RS232 converter between your Arduino and the PC.

A TTL to USB converter is much more convenient, (and cheaper).

thanks so that means the FTDI converter is essential.

ransaraw: thanks so that means the FTDI converter is essential.

No, not essential, just more convenient. As I said, you could use a TTL to RS232 converter and connect to a PC serial port.