title: What's the difference between a vector and a vertex?
body: <p>I often see the words 'vector' and 'vertex' (plural 'vertices') being used in 3D programming contexts. </p>
  
  <p>From what I can tell, they both describe a point in n-dimensional space. The XNA framework for example has Vector2, Vector3 and Vector4 classes, but there doesn't seem to be a Vertex class.</p>
  
  <p>What is the exact difference between a vector and a vertex?</p>