As we learn more about the different Newton laws, we had assignments to draw out free body diagrams, which show something happening and all the forces acting on it. One example I remember is something being suspended in the air, its like the opposite of something resting on a table. The picture above shows a light bulb being held in mid air by a wire. The reason that the light bulb isn't free floating is because gravity is acting on it. It causes the light bulb to hang freely. The reason it doesn't fall is obviously the wire, but the wire has tension, the normal force. Just as if a box resting on a table. The normal force is the table pushing back on the box, causing it to stay at equilibrium. The tension in this case is the same thing as the tables force normal. When going over examples on a work sheet I didn't realize how common these things are, it shows how physics works around us everyday.