title: What is the meaning/reason for the generated entries in web.config>configuration>runtime>assemblyBinding?
body: <p>I've noticed this section in my web.config files for a while and I'm now trying to reason out what exactly the purpose is:</p>
  
  <pre><code>  &lt;runtime&gt;
      &lt;assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1"&gt;
        &lt;dependentAssembly&gt;
          &lt;assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" /&gt;
          &lt;bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" /&gt;
        &lt;/dependentAssembly&gt;
        &lt;dependentAssembly&gt;
          &lt;assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" /&gt;
          &lt;bindingRedirect oldVersion="0.0.0.0-4.0.0.0" newVersion="4.0.0.0" /&gt;
        &lt;/dependentAssembly&gt;
        &lt;dependentAssembly&gt;
          &lt;assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" /&gt;
          &lt;bindingRedirect oldVersion="1.0.0.0-2.0.0.0" newVersion="2.0.0.0" /&gt;
        &lt;/dependentAssembly&gt;
      &lt;/assemblyBinding&gt;
    &lt;/runtime&gt;
  </code></pre>
  
  <p>So, the first entry seems to say:</p>
  
  <blockquote>
    <p>System.Web.Helpers is the name of a dependent assembly with a public
    key token of <code>31bf3856ad364e35</code>. Redirect version 1.0.0.0 through
    2.0.0.0 to version 2.0.0.0.</p>
  </blockquote>
  
  <p>My best guess is that it means any code executing in the context of the ASP.NET run time that depends on an assembly with the specified name which also has a version in the specified range executes as if it were compiled with the specified version with the specified public key.</p>
  
  <p>Does this mean if I have a web project that depends on a class library and that class library has a reference to an older version of the assembly which has a a bindingRedirect, that the code will execute as if it were compiled against the newer version?</p>