title: Is Stochastic gradient descent a classifier or an optimizer?
body: <p>I am new to Machine Learning and I am trying analyze the classification algorithm for a project of mine. I came across <code>SGDClassifier</code> in <code>sklearn</code> library. But a lot of papers have referred to SGD as an optimization technique. Can someone please explain how is <code>SGDClassifier</code> implemented?</p>