title: Clarification on Conv2D() syntax in keras
body: <p>This is a line of code taken from the CIFAR-10 CNN example on the keras website.
  <a href="https://keras.io/examples/cifar10_cnn/" rel="nofollow noreferrer">https://keras.io/examples/cifar10_cnn/</a></p>
  
  <p>The dataset consists of </p>
  
  <pre><code>model.add(Conv2D(32, (3, 3), padding='same',
                   input_shape=x_train.shape[1:]))
  </code></pre>
  
  <p>What does the 32 after the <code>(</code> mean and what is the default stride length? </p>