What do noncoplanar lines look like?

Answer 1

Two lines, in 3-dimensional space must either intersect, be parallel or be skew. In the first two cases, they are coplanar which leaves skew lines.

One way to "see" what they look like is to imagine you are standing in a cuboid room. Consider the edge where the walls on your left and the one facing you meet. Next, consider any non-vertical line of the wall to your right. [A vertical line will be parallel to the first]. These two lines will be skew. They are not parallel and also they never intersect.