Sigh, one of these users. Fine, lets do it since I'm bored and don't mind lecture someone.
The OP clearly ask how to ask to install an xci file. The difference between the format wasn't very well explained by you or any other. Some where a lot better than other.
XCI is a file format, mostly used with the dumping of the cartridge. XCI files can be both installed and (only) mounted via SXOS. NSP files are "packaged" that need to be installed via an installer.
NSP files can be made via a lot of methods. It's not only "eshop" titles. Some of them are converted from XCI to NSP. Aka. just repacked in to another format.
So do please explain how my moderation responsibility has anything to do with correcting you? Stop being a jerk and just accept that you got corrected. Plain and simple.