Ok, how about we start with what is TTY.It stands for “teletypewriter.” What can tty tell us. In Linux, there is a pseudo-teletype multiplexor which handles the connections from all of the terminal window pseudo-teletypes (PTS). The multiplexor is the master, and the PTS are the "slaves". The multiplexor is addressed by the kernel through the device file located at /dev/ptmx. The tty command will print the name of the device file that your pseudo-teletype slave is using to interface to the master. And that, effectively, is the number of your terminal window. The output shows that we are connected to to the device file at /dev/pts/4. Our terminal window, which is a software emulation of a teletype (TTY), is interfaced to the pseudo-teletype multiplexor as a pseudo-teletype (PTS). And it happens to be number four.For the number at the end shows that. The Silent Option . The -s (silent) option causes tty to generate no output. This is how it will look on your terminal It do...