From Turn.js Documentation
A view contains the pages that are visible. Technically, it's an array of two values if the display is set to double page or one value if the display is single.
Examples of views
- if the display is set to double, a flipbook of 8 pages would have the following views
[0,1] [2,3] [4,5] [6,7] [8, 0]
- if the display is set to single, a 4 pages long flipbook would have the following views
   
Main Page > Views