Negative space is basically the area behind an object in a picture of piece of artwork. This includes anything above, below, and on the sides of the object(s) you are looking at.
I found negative space in my "Cut Out" by first identifying the object I was looking at. The objects are a house with a fence and clouds in the sky. Only half of the paper was done at a time (left and right). On the paper, before cutting and tracing, was two separate colors (light gray and dark gray). The dark gray color covered all the objects I was looking at (the house, fence, and clouds). The insides of the windows of the house were also dark gray, along with other details of the house. All of the light gray area was the negative space. After cutting and tracing, the colors changed for negative space on two different sides. The negative space is now blue on the left side and one the right it is light green.
I found negative space in my "Stool Drawing" after I identified the objects that I was looking at. The objects are a table, two stools (one on top of another), a plant, and a chord hanging from the ceiling. First, I took a white piece of paper and shaded it completely with a pencil. I then took my eraser and erased any part of the objects that i saw until they were white like the paper before shading. Now I can tell the objects from the non-objects. The non-objects are the negative space, which is the shaded part of the paper.
It helps an artist to see in negative space because I believe it makes it easier to shape the object they are trying to create. It is useful in creating art by being a short cut. When I say this I mean it can help others who are not proud of their drawing skills. This is one way you don't need to know how to draw to complete.