/home/username/etc/,passwd, ????

[HeadSage]

Can someone share your knowledge on ,passwd, ; ,quota, and ,shadow, file found at /home/username/etc/ dirs..Only some accounts have the files..AFAIK /home/username/etc/passwd and /home/username/etc/shadow are the files which hold the password and other information about the mail accounts..

I am confused in understanding the file format starting with comma i.e ,passwd, ,shadow, or ,quota,..

I value your comments..Please share yours..

Also I did an extensive search on forums..If it is already discussed anywhere else I will appreciate it much if you could provide me the link..

Thanks in advance
John

 

[HeadSage]

Please share your knowledge about those files..I am totally clueless on how and why they are created..

Regards
John