Let us assume a scenario, you are coming back after holiday, and generally it happens that you don't remember your system password. Now, what to do. Don't worry here are the steps which will help you in resetting the password.
Lets get started with the process.
Linux will boot in run level 1 with root user logged in. From here we can change password of root user or any other user. Change the password using passwd command. Enter the new password. Retype the password. And reboot the system with default sequence. Once the system is ready to login, use the new credentials to log in.