What command is used in Linux to change a user's password?

The command used in Linux to change a user's password is "passwd." This command prompts the system to ask for the current password (if required) and then requests the new password before confirming the change. It is a widely used and standard command across various Linux distributions, designed specifically for managing user passwords effectively.

In comparison, the other options do not correspond to standard Linux commands for changing a password. "change-pass" and "reset-password" are not valid commands recognized in the Linux command line landscape, reflecting either confusion with terminal syntax or non-existent functionalities. The command "user-mod" is used for modifying user accounts but not specifically for changing passwords, as its purpose is broader and encompasses various account attributes like user home directories, group memberships, and login shells. Understanding the functionality and correct usage of these commands is essential for effective Linux system administration.