fhau013 0 Newbie Poster

hello there can someone explain to me in an easier way what are these im a new employee in in telecommunication company viop services

SIP-
CTI-
RFC-
PBX-
IP PBX-
PSTN-
CRM-
TAPI-
API-

in the most simplist form cause i cant really understand these pls bare with me thank you so muchhh :)