Chessbase products - difference Since the ChessBase website is rather unclear, I would like help regarding a few issues:

I have a few questions.


What is the main differences between the Big Database and the Opening Encyclopedia?
Does the Opening Encyclopedia require purchase of ChessBase separately, or is it a program in of itself?
Does either of these below products require a DVD player or is there a downloadable version?
ChessBase, Big Database, Opening Encyclopedia
Big Database is a large (6.8 million) collection of unannotated games. Opening Encyclopedia has slightly fewer games (probably games of lower quality are left out), but also contains 6000 opening surveys, 85 000 annotated games, and opening articles from older issues of ChessBase Magazine.
It seems Opening Encyclopedia comes with ChessBase Reader 2013 included. This lets you access the whole content of the Opening Encyclopedia, but it doesn't have the full functionality of ChessBase 14. With the Reader you cannot modify the bases or add your own games and analysis. 
All the products you mention are available to buy and download from ChessBase Shop.