Interpersonal Communication or IRC as I like to remember it by, is the communication between oneself and another individual.
it could range anywhere from saying good morning to a random passerby on your walk to work, to talking to a friend about going to the cafe on Friday, to asking out your friend/crush of several years on a date.
Something interesting about IRC is that its much more subject to being misunderstood. when your talking to somebody about something and you don't get a point across or misstructure your communication there can be a misunderstanding which can lead to unintended things like confusion, anger, shock, etc. so being good at IRC is pretty important because you don't want any miscommunications