Change password in linux

passwd - entering just passwd would allow you to change the password. After entering passwd you will receive the following three prompts:

Current Password:
New Password:
Confirm New Password:

Each of these prompts must be entered and entered correctly for the password to be successfully changed.

passwd newperson

If you have just setup an account using the useradd command you would then type a command similar to the above command to set the password for the "newperson" account. Only root users have the ability to set passwords for other accounts.