A Convolutional Neural Network (CNN) diagram is an artificial neural network used in image recognition and processing that is specifically designed to process pixel data. As the diagram below illustrates, CNN diagrams are used mainly for image processing, classification, segmentation, and other autocorrelated data. A convolution is essentially sliding a filter over the input. In simpler words, each neuron works in its receptive field and is later connected to other neurons in the network in a way that covers the entire visual field. The core example of the CNN diagram is how face recognition works in computer vision.