The new macbook macbook pro and macbook air models are equipped with a mini display port and you can connect an external screen via this or an adapter or projector an external screen can be used as main working area or for expansion of your working table or you can work in the screnn syncronisation mode with a projector so you can see always what is shown publically on a projectoryou can use the mini displayport on vga adapter to connect a conventional analog monitor projector or lcd sc