Biological inspiration

ANNs are loosely inspired by how animals' brains work. Our brain is a complex network of neurons, each passing information to each other and processing sensory inputs (as electrical and chemical signals) into thoughts and actions. Each neuron receives its electrical inputs from its dendrites, which are cell fibers that propagate the electrical signal from the synapses (the junctions with preceding neurons) to the soma (the neuron's main body). If the accumulated electrical stimulation exceeds a specific threshold, the cell is activated and the electrical impulse is propagated further to the next neurons through the cell's axon (the neuron's output cable, ending with several synapses linking to other neurons). Each neuron can, therefore, be seen as a really simple signal processing unit, which—once stacked together—can achieve the thoughts we are having right now, for instance.