Neurons and glia make up the central nervous system and the peripheral nervous system. The responsibility of the central nervous system is to receive information from the body and integrate it to coordinate various responses. For example, if you see a ball flying at your face, you probably want to duck or jump out of the way, right? This is the sensory information that your brain processes, and then it coordinates a response and sends it out to your peripheral nervous system to actually act out that movement. The brain is really like the control center for all of this, and the spinal cord is essentially just a bundle of neurons and glia that extend down from the brain, branching out into all the different nerves of the peripheral nervous system.
The peripheral nervous system sends signals to and from the brain and spinal cord and contains little clusters of cell bodies that are also seen in the central nervous system, but they have a different name. We call them ganglia; 'ganglion' is the singular, and 'ganglia' would be the plural. This is just a cluster of neuron cell bodies. The nerves are made up of bundles of axons, and often the neuron cell bodies are all clustered together in one place. These bundles of axons are broken down into two categories: sensory and motor neurons. Sensory neurons transmit sensory information ultimately to the brain and spinal cord, bringing in information from our sensory systems. Motor neurons project from the spine out to effector organs like muscles and glands, sending signals to act, such as ducking when you see a ball coming towards your face.
You will also see what are called interneurons, which are neurons that transmit information between other neurons. They connect, sometimes, sensory and motor neurons, although sometimes sensory and motor neurons will directly connect to each other. What's important to note, however, is that interneurons are the main type of neuron in the brain. Now, with that, let's go ahead and flip the page.