What do pty and tty mean?

Question

I noticed there are many mentions of pty and tty in some opensource projects, could someone can tell me what do they mean and what is the differenc

Answer 1

tty: teletype. Usually refers to the serial ports of a computer, to which terminals were attached.

pty: pseudoteletype. Kernel provided pseudoserial port connected to programs emulating terminals, such as xterm, or screen.