title: Hyper-parameters of Gaussian Processes for Regression
body: <p>I know a Gaussian Process Regression model is mainly specified by its covariance matrix and the free hyper-parameters act as the 'weights'of the model. But could anyone explain what do the 2 hyper-parameters (length-scale &amp; amplitude) in the covariance matrix represent (since they are not 'real' parameters)? I'm a little confused on the 'actual' meaning of these 2 parameters.</p>
  
  <p>Thank you for your help in advance. :) </p>