Suppose you are a go to person among your friends and family when it comes to Linux related questions. Someone asked you how to install and configure a tool, and you wanted to show the procedures. How would you do that if he or she is not in front of you? There could be various ways (e.g., by documenting and emailing the procedures, or explaining verbally over the phone, etc), but probably the most clearcut solution would be to demonstrate it yourself. If the demonstration only requires a terminal, then the best way would be use terminal screencast or terminal session recorder.