complete newbie here. Can someone please tell me what /dev/ttyAMA0. I read that it is the TxRx pins. But what is it? is it used to refer to the pins or their address? is it explicitly the Rx or the tx pin?
@Milliways had the best answer in my opinion. His answer can be found here: Link given here
ttyAMA0 can be the Tx, Rx pins for the Raspberry. But for the Raspberry Pi 3b it was used for the Bluetooth. Because of this, pins 8 & 10 were using the miniUART which is labeled ttyS0 (unless you disable the Bluetooth which has instructions in that link in the beginning of this post)
So to answer you question, it can refer to pins 8 and 10 if you disable the Bluetooth. It is both the RX and TX pins as it refers to the device it self, which contains both pins.
I hope this and the answer by Milliways helps you out.