Question

what is nested frames

Answer 1

This element specifies a frameset which has been nested within another frameset within a WordprocessingML document. This WordprocessingML element is analogous to the frameset element in HTML (when that frameset is the child of another frameset element).

Answer 2

Explanation:

Nesting frames

The nested <frameset> tag occupies one frame position within the containing frameset but can have any sort of layout within it. This lets you create a frame layout, for example, with one row of two frames and another row with three frames.