presenter

Short definition from Wiktionary

Noun

1. 1
   Someone who presents a broadcast programme; a compere or master of ceremonies.
2. 2
   Someone who presents a thing or person to someone else.
3. 3
   A small handheld device used to remotely control a computerised slide show.
4. 4
   A conceptual layer in GUI-based software that assumes the functionality of the "middleman".