There are two main types of cells in the nervous system: neurones, which connect and send electrochemical signals to each other; and glial cells which maintain the environment needed for neuronal function.
Central nervous system
Peripheral nervous system
Autonomic nervous system
The nervous system is quite useful. If I had to choose between having a brain or having a spleen, it would not be a decision that would take me very long. However, understanding how it works is not fun. Learn about sympathetic and parasympathetic pathways. I assume there will be more to write in this section soon.