What does TTY mean in the unix ps command?

Question

When I run PS one of the columns output is TTY. What does this mean? In particular, how does as value of \"??\" compare with \"ttys000\"?

I ask because I have a Java p

Answer 1

A process can be (and usually is) bound to a "controlling terminal". This terminal may be hardware at the end of a serial line, or much more likely today, be a virtual software equivalent. The TTY is inherited from the parent process. Most likely your IDE disassociates itself from its TTY, and when started outside your java program inherits your shell's TTY.

Answer 2

A TTY is a computer terminal. In the context of ps, it is the terminal that executed a particular command.

The abbreviation stands for "TeleTYpewriter", which were devices that allowed users to connect to early computers.

In relation to your situation, the jar creates a virtual terminal named 'ttys000' but the IDE does not attach to a virtual terminal to execute the command.