Passwd is a tool used to change a user's password.

# To change the password of the current user interactively:
passwd

# To change the password of the current user:
passwd <new_password>

# To change the password of the specified user:
passwd <username> <new_password>

# To get the current status of the user:
passwd -S

# To make the password of the account blank (it will set the named account passwordless):
passwd -d