As mentioned, what is the difference? or is there any concern to use them?
Unlike DOS-based OSes, in Unix and Linux file extensions are mostly meaningless outside of human-readable reasons. INI is a configuration file standard.
A .conf file could be an INI file, or it could be any other configuration system that the application supports. MySQL, for example, uses the file
INI files has a format roughly like this:
The line endings are usually
Conf files, on the other hand, are more varied. They may have the same formatting as ini files, or something completely different, like this:
.conf files usually have the unix style line endings, at lest on unix-like systems. It is frowned upon for .conf files on unix-like systems to have windows style line endings.
TL;DR; ini files usually have windows style line endings and a fixed layout, while conf files have their roots in unix-like systems and can have almost any kind of layout