Linux file system permission - What is the difference between chmod and chown commands?

The chmod and chown commands in Linux are used for changing permissions on a file or directory.

1. chmod: This command is used to change the permissions of a file or directory. In Linux, there are three types of permissions that can be assigned: read (r), write (w), and execute (x). Each file or directory has three user based permission groups: owner, group, and others. The chmod command allows you to change these permissions. For example, the command "chmod 755 filename" would change the permissions of "filename" to read, write, and execute for the owner, and read and execute for the group and others.

2. chown: This command is used to change the owner and group of a file or directory. For example, the command "chown username filename" would change the owner of "filename" to "username". You can also change the group at the same time by using a colon to separate the user and group, like "chown user:group filename".

In summary, chmod is used to change the permissions of a file or directory, while chown is used to change the owner and group.