# What's the difference between convolutional neural network and convolutional auto encoders?

What's the difference between convolutional neural network and convolutional auto-encoders?

This paper explains both but I find it hard to pinpoint the difference: http://people.idsia.ch/~juergen/icann2011stack.pdf

Many thanks!

A convolutional autoencoder is a type of convolutional neural network. However people probably refer to convolutional neural networks as supervised convolutional neural networks, i.e. with a softmax classifier or a SVM classifier on top while a convolutional autoencoder is an unsupervised network, so it tries to reconstruct the input using learned features and might have an $L2$ error loss like $\|f(x) - x \|_2$ where $f(x)$ is the network output and $x$ is the input image. The term autoencoder is used to represent the fact that we are trying to reconstruct the input, and thus requires no labels.