I'm trying to understand how file permissions work in Ubuntu. However, I can't understand the difference between user and group permissions.
In here it says:
Owner permissions − The owner's permissions determine what actions the
owner of the file can perform on the file.
But it also says:
Group permissions − The group's permissions determine what actions a
user, who is a member of the group that a file belongs to, can perform
on the file.
So does a file belong to a user or a group? If the 2nd column shows the group permissions, how can those permissions be any different from the user ones?