The practical aspects of communicating with others, or the social “niceties” of language, are referred to as

The practical aspects of communicating with others, or the social “niceties” of language, are referred to as pragmatics. 
Pragmatics deals with language in use and the contexts in which it is used. So, your use of language will change depending on the social situation or the people you are talking to.

The answer isharmonia which was written by rythem. 

Your account is deleted, so i guess there's no point in answering. also the question was in the wrong subject. just an fyi: you can bold by using control+b. italicize by using control+i. and underline by using control+u.