title: Entity vs Model vs View Model
body: <p>I just spent some time reading about these terms (I don't use them that much since we don't have any MVC applications and I usually just say &quot;model&quot;), but I have the feeling these means different things depending on the context:</p>
  <p><strong>Entity</strong></p>
  <p>This is quite simple, it is one row in the database:</p>
  <blockquote>
  <ol start="2">
  <li>In relation to a database , an entity is a single person, place, or
  thing about which data can be stored.</li>
  </ol>
  </blockquote>
  <p><strong>Model</strong></p>
  <p>I often read, this is basically a combination of entities to represent a full set of data, let's say an Addresslist-model of a customer would combine the entities customer, address and probably individual.</p>
  <p><strong>Viewmodel</strong></p>
  <p>A term in the MVVM or MVC patterns, which is a model, which represents exactly the data you can see on the view. The viewmodel is on the application tier and has attributes for validation, e.g. <a href="https://stackoverflow.com/questions/4061440/asp-net-mvc-model-vs-viewmodel">ASP.NET MVC Model vs ViewModel</a></p>
  <p>From my sight, these terms seem all a bit redundant: The Viewmodel has obviously his use, otherwise the view would have to do all the hard work to show the right stuff. The entity is just the representation, as we know from the EF, but if you combine these two, where has the model his use?</p>
  <p>Stuff like validation, security etc. has to be done on the ViewModel. Would you use the model when you have hundreds of small tables to put another abstraction between the entities and the viewmodel? Or Are in terms of MVC and MVVM entities and models usually the same?</p>
  <p>As usual thanks and a nice weekend</p>
  <p>Matthias</p>