What does GID mean?

view full story

http://unix.stackexchange.com – What does GID actually mean? I have Googled it and this is what linux.about.com said: Group identification number for the process. Valid group numbers are given in /etc/group, and in the GID field of /etc/passwd file. When a process is started, its GID is set to the GID of its parent process. But what does that mean? The permissions I have for my folder is currently at 0755 I understand if I set the UID for the Owner it will be 4755 And if I set the GID of the Group it will be 2755 If I set the Sticky Bit for Others it will be 1755 Is it even important to set those permissions? (HowTos)