What does the 'chmod' command in Linux do?

The 'chmod' command in Linux is specifically designed to change the permissions associated with a file or directory. In a Unix-like operating system, every file and directory has an associated set of permissions that determine who can read, write, or execute that file. The 'chmod' command allows users to modify these permissions for different categories of users: the owner of the file, members of the file's group, and all other users.

When 'chmod' is used, it can set permissions either using symbolic references (like 'r' for read, 'w' for write, and 'x' for execute) or by setting numerical values that represent those permissions in octal format. This flexibility makes it a powerful tool for managing access controls in a secure and efficient manner.

Other options describe different functions that are not related to 'chmod'. Changing file metadata or ownership involves different commands such as 'chown' for changing ownership and 'touch' for updating timestamps or metadata. Moving or changing the location of files typically involves the 'mv' command. Therefore, these options do not accurately reflect the specific purpose of 'chmod'.