What is the purpose of the 'chmod' command?

The 'chmod' command is specifically designed to change file permissions in a Linux operating system. This command allows users to modify who can read, write, or execute a file or directory. File permissions are a fundamental aspect of access control in Linux, determining what users and processes can do with files.

When using 'chmod', you can set permissions for the file owner, the group associated with the file, and all other users. This can be done using either symbolic notation (like 'u+rwx' for the user, 'g+rw' for the group, etc.) or numeric (octal) notation (like '755', which indicates specific permissions for owner, group, and others). By controlling these permissions, administrators can enhance security and manage access effectively in a multi-user environment.

The other choices relate to different functionalities within the Linux environment: changing file ownership is managed by the 'chown' command, moving files is done with the 'mv' command, and creating a directory is performed using the 'mkdir' command. These commands are critical as well, but they serve different purposes than 'chmod'.