Supervised Learning
Each training case consists of an input vector x and a
desired output y (there may be multiple desired outputs
but we will ignore that for now)
Regression: Desired output is a real number
Classification: Desired output is a class label (1 or 0
is the simplest case).
We start by choosing a model-class
A model-class is a way of using some numerical
parameters,   W,  to map  each input vector, x, into a
predicted output y
Learning usually means adjusting the parameters to
reduce the discrepancy between the desired output on
each training case and the actual output produced by
the model.