A junction, or node, in a neural network. A neuron is a data element, not physical hardware. Large AI models can have more than a billion neurons and more than hundreds of billions of interconnections that are adjustable (parameters). It is the fine tuning of these parameters that shapes a model for its intended purpose.
The human brain, from which the neural network is loosely modeled, is estimated to have at least 85 billion neurons, each of which is a living cell. See
neural network and
SNARC.