passwd command in Linux is used to change the user account passwords. The root user reserves the privilege to change the password for any user on the system, while a normal user can only change the account password for his or her own account.

How do I find out my Linux password?

The /etc/passwd is the password file that stores each user account. The /etc/shadow file stores contain the password information for the user account and optional aging information. The /etc/group file is a text file that defines the groups on the system. There is one entry per line.

What is the default Linux password?

Password authentication via /etc/passwd and /etc/shadow is the usual default. There is no default password. A user is not required to have a password. In a typical setup a user without a password will be unable to authenticate with the use of a password.