Parallel lines are lines that have the same direction and there is always the same distance between them
Skew lines are lines that are not on the same plane (they are not coplanar) and also they do not intersect.
Intersecting lines are lines that cross at a point, they can be on the same plane or on different planes.
Let's analyze the parts of this problem.
DE and AB.
These two lines are shown in red and blue in the following diagram:
These are not parallel lines because one line is vertical and the other line is horizontal. They are also not intersecting lines because they do not cross at any point. Lines DE and AB are skew lines because they do not intersect and they are on different planes.
--> DE and AB --> skew
CB and