Let me explain first of all what neurons are and how they are structured. The following labelled diagram shows a typical neuron:

We define neuron as an electrically excitable cell that receives, processes, and transmits information through electric and chemical signals. A dendrite is a part of it that receives signals from other neurons. One thing that we need to pay attention to is that just a single neuron can't do anything and there are billions of neurons connected to each other, which enables the electro-chemical signal flow and, in turn, the information to flow through it. The information passes through an axon and a synapse, before being transmitted.

When it comes to a neural network, the structure doesn't change much. Let's have a look at it. In the middle, we have a neuron and this neuron gets signals from three other neurons, X1, X2, and X3. All three neurons are connected by arrows that act like a synapse. These neurons, X1, X2, and X3, are called input layer neurons...