ReLU:  activation function; usually, we apply an activation after each layer.
.view: This is for changing the shape of tensors without copying it.
Linear layer: it is also called Fully Connected layer. In Pytorch a FC takes in an input that’s 2D.
fc1/2/3: That’s just variable names.
“Calling maxpool2d after Conv2d”: Take a look at the common structure of a Conv net.
channels: Channels are originally used for describing colors of an image, for example RGB images have 3 channels. Here, “channel” represents a dimension of the tensor, it is usually the second dimension of an input tensor for Conv2d.
Taking a look at this page 48 would probably get u some help.