How do neural networks work?

Similar to the biological neuron structure, ANNs define the neuron as a central processing unit, which performs a mathematical operation to generate one output from a set of inputs. The output of a neuron is a function of the weighted sum of the inputs plus the bias. Each neuron performs a very simple operation that involves activating if the total amount of signal received exceeds an activation threshold, as shown in the following figure:

The function of the entire neural network is simply the computation of the outputs of all the neurons, which is an entirely deterministic calculation. Essentially, ANN is a set of mathematical function approximations. We would now be introducing new terminology associated with ANNs:

• Input layer
• Hidden layer
• Output layer
• Weights
• Bias
• Activation functions