What are pseudo-tty devices? can any body guide me guide or tutorial where all the devices are listed with their use?

The reason for posting the thread is i m doing server hardening .It is not recommended to include pseudo-tty devices in /etc/securetty file .

Following are the statement from hardening guide.
Correct me if i m wrong.
locally attached console devices which are normally determined using w command.
For example .
These ttys can be taken by physically logging in to machine and using (alt+f1-f6).Therefore we can have upto 6 local tty devices.


Are they begins with p.
following is a content from my /etc/securetty.

Hi,

In addition to the 'man' you can look at the following to gain some understanding;
Linux Documentation Project
Rute Tutorial & Exposition
Linux Command Guide
Linux Newbie Admin Guide
LinuxSelfHelp
Getting Started with Linux



The above links and others can be found at 'Slackware-Links'. More than just Slackware® links!