Here's a breakdown:

* The central oxygen atom: The two oxygen atoms are connected by a single bond and each has two lone pairs of electrons.

* The hydrogen atoms: Each hydrogen atom is attached to one of the oxygen atoms.

* The dihedral angle: The two planes defined by the H-O-O-H atoms are not perfectly aligned. Instead, they form a slightly twisted, non-planar structure.

Why is it non-planar?

The non-planar structure is due to the repulsive forces between the lone pairs of electrons on the oxygen atoms. These forces push the hydrogen atoms slightly out of the plane, resulting in the twisted, open-book shape.

Here's a visual analogy: Imagine opening a book slightly. The two pages are not perfectly flat, but they are slightly tilted. This is similar to the structure of hydrogen peroxide.

Note: Although the structure is often represented as a planar structure in textbooks, it is important to remember that it is actually non-planar.