After two rounds of convolution and pooling, our tensors have gotten relatively small and deep. After pool_2, the output dimension is (n, 6, 6, 32).

We have, in these convolutional layers, hopefully extracted relevant image features that this 6 x 6 x 32 tensor represents. To classify images, using these features, we will connect this tensor to a few fully connected layers, before we go to our final output layer.

In this example, I'll use a 512-neuron fully connected layer, a 256-neuron fully connected layer, and finally, the 10-neuron output layer. I'll also be using dropout to help prevent overfitting, but only a very little bit! The code for this process is given as follows for your reference:

from keras.layers import Flatten, Dense, Dropout
# fully connected layers
flatten = Flatten()(pool2)
fc1 = Dense(512, activation="relu", name="fc1")(flatten)
d1 = Dropout(rate=0.2, name="dropout1")(fc1)
fc2 = Dense(256, activation="relu", name="fc2")(d1)
d2 = Dropout(rate=0.2, name="dropout2")(fc2)

I haven't previously mentioned the flatten layer above. The flatten layer does exactly what its name suggests. It flattens the n x 6 x 6 x 32 tensor into an n x 1152 vector. This will serve as an input to the fully connected layers.