What is Pseudo TTY terminal?

 A Pseudo TTY means Pseudo Terminal, a software emulated terminal that behaves like real terminal device. Usually scenarios like SSH sessions.

In simple terms,

A TTY is the terminal interface itself.

A PTY is a fake/software version of that terminal, with a master side and a slave side.

Example

When you open a terminal window or connect over SSH, your shell is usually talking through a pseudo tty rather than a physical terminal.

***