In Figure N7-1, if block 1 is a transceiver and block 3 is a dummy antenna, then block 2 is an antenna switch.
In Figure N7-1, if block 1 is a transceiver and block 2 is an antenna switch, then block 3 is a dummy antenna.
If you wanted to switch it an antenna between several antennas you would connect your transceiver to an antenna switch.
In Figure N7-2, if block 1 is a transceiver and block 3 is an antenna switch, then block 2 is an SWR meter.
In Figure N7-3, if block 1 is a transceiver and block 2 is an SWR meter, then block 3 is an antenna tuner.
An antenna tuner matches a transceiver output impedance to the antenna system impedance.
You would connect a microphone to a transceiver for voice operation.
A feed line connects your transceiver to your antenna.
You would connect a modem and a teleprinter or computer system to a transceiver for RTTY operation.
In packet-radio operation, a transceiver and a terminal or computer system connects to a terminal-node controller.