A nerve cell is the major signally unit of the nervous system. A stimulus comes to the body, stimulates a nerve cells which sends the message to other nerve cells. There are 100 billion nerve cells in the brain, as many as stars in our galaxy. Each of these nerve cells can contact as many as 10,000 other nerve cells. Through the wiring set-up during development, and modified by learning, these nerve cells can generate complex behavior.
Glial cells are the metabolic and structural support cells for the nerve cells.
In general the nerve cells do not divide after birth, for example, in the outer layers of your brain you do not get new nerve cells after you are born. You must live your full one hundred years with the same nerve cells, but the glial cells do divide. Glial cells are more numerous than nerve cells. Don't ever sell glial cells short. They play an active role in establishing and maintaining the fundamental patterns of neuron circuits.