Configuration files are typically stored in the /etc directory. They can, of course, be anywhere the implementer wishes them to be as long as the process knows where to find them.
/etc/login.defs and /etc/passwd
The user's name is stored in /etc/passwd and/or /etc/shadow. The user's data is stored in the /home directory.
/boot
C:\windows
System-wide configuration files are usually found in /etc. Personalized configuration files are stored in the user's home directory, in files and subdirectories preceded by a "." in their name.
Name resulution can be provided statically with /etc/hosts which usually contains IP addresses along with corresponding domain names, like: 127.0.0.1 localhost localhost.localdomain 127.0.0.2 test.localhost or dynamically, by performing requests to name servers specified in /etc/resolv.conf . Authentication data for local users is held within several files: /etc/group which contains list of existing groups and memberships, /etc/passwd which contains list of existing users and their attributes like home directory and, if the system has been configured to utilize shadow passwords, /etc/shadow which contains encrypted passwords along with additional account attributes like expiration time.
Boot Configuration Data (BCD) is stored in a file called BCD located in the \Boot directory of the system partition on Windows operating systems. This partition is typically marked as active and may not have a drive letter assigned. The BCD file contains boot configuration parameters and controls how the operating system is started. It can be accessed and modified using tools like bcdedit in the command prompt.
Use the command 'passwd'
It depends on system to system. Basically you can find that out by looking at the file "/etc/passwd" You can filter out the username you want to check using "cat /etc/passwd | grep username"
Ram
These two directories are used for different purposes. The /tmp file system is for creating/using temporary files and directories and may be cleaned as a result of a reboot. Scratch files created by utilities and compilers are placed here, and the directory is readable and writable by anyone. The /etc directory is only writeable by an administrator, and contains most of the system configuration file information in multiple directories and files.
In Unix, the parent directory is the directory that contains the current directory. It is represented by the symbol .. (two dots). When navigating the file system, you can use this symbol to move up one level in the directory hierarchy. For example, if you are in /home/user/documents, the parent directory would be /home/user.