In linguistics, a phatic expression /ˈfætɪk/ is communication which serves a social function, such as social pleasantries that don't seek or offer any information of value.[1] Phatic expressions are a socio-pragmatic function and are used in everyday conversational exchange typically expressed in situational instances that call for social cues.[2] In speech communication the term means "small talk" (conversation for its own sake) and has also been called "grooming talking."[3]
https://en.wikipedia.org/wiki/Phatic_expression
See also:
http://www.signosemio.com/jakobson/functions-of-language.asp