 My name's Andy. I'm part of the training department here at Riedel Communications. In this series of videos we're going to be looking at some of the terms that we use when we're talking about the elements of an intercom system. There may be a lot of words that you already know in normal English usage but in the intercom world they can have slightly different meanings which is why we're going to go through here and explain what they mean so that as you're watching the other videos in this series you'll actually know what we're talking about.