Note
This page is for computer processes. I don’t know why you’d ever make one about the English term, but hey, in case you do, you’ve now got a clear distinction.
What
It’s an instance of a program that’s currently executing. It has states. About:
- They must be loaded into Virtual Memory and uniquely identified (
pid
). pid
’s have CPU times, memory usage, user ID that spawned it -uid
, etc.- Processes might control other processes (fork).
- Child process inherits context from parent process.
What can it do?
- By default, the process only has the privileges that it’s parent
uid
has.
Permissions! (Lowkey quite cool)
Every process has 3 user IDs:
- Real User ID (
uid
): The user ID that actually started the process - Effective User ID (
euid
): The user ID that determines the process’ privileges. For example, you may want to temporarily runsudo
, at which point the terminal’s command changes itseuid
to0
(root’s). - Saved UserID (
suid
): We save the user ID before changing theeuid
so we can go back to it.