You know that kid in the back of the room who never raises their hand or speaks up. They might say two words to you when you ask them a question, but that's it. Maybe they do their work, maybe not. Maybe you are like me and, ( ok, I might be shooting myself in the foot by admitting this...) you may not notice right away when they are absent.
Part of creating a culture that subscribes to the LaSallian principles of AGAPE ( Association, Generativity, Adaptation, Presence, and Engagement) is creating an environment where students feel like they are a part of something. Specifically, they need to feel a part of the classroom community. With specific regard to Presence, students need to feel like they have a presence it he classroom.
Let me also take a moment to be realistic here...there are always some students who have a little too much presence in your classes. By no means do I mean that you want to have 30 of those wonderfully enthusiastic and excited students in your classroom just ready to explode from their desks. Those students are special in their own way...but true Presence means that all students feel like they are a valued member of your class the way they are. Students feel welcomed and valued by you, the teach, and the other students in the class. They should never feel like they are invisible.
Presence not only refers to how the students feel in your class, but also how you carry yourself as a teacher. I hope that none of you reading this are the teachers who teach and then sit at the desk to grade papers. If so, you have no presence. Plain and simple. Teachers with presence are out in the trenches working with students so that they know you are always there and approachable.
So to sum it up, presence is making your kids feel like they are not just in the room, but a part of something with a voice. It is also making sure students know that you are there for them.