http://blogs.msdn.com/jmeier/archive/2008/09/06/layers-and-tiers.aspxAs part of the patterns &amp; practices App Arch Guide 2.0 project , we needed to nail down layers and tiers. Layers vs. Tiers The original App Arch Guide distinguished between layers and tiers: "This guide uses the term layer to refer to a componenten-USCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.msdn.com/jmeier/archive/2008/09/06/layers-and-tiers.aspx#8929799Sun, 07 Sep 2008 06:48:49 GMT91d46819-8472-40ad-a661-2c78acb4018c:8929799J.D. Meier's Blog<p>In my previous post, I summarized layers and tiers . In this post, I'll walk through the key components</p> http://blogs.msdn.com/jmeier/archive/2008/09/06/layers-and-tiers.aspx#9130799Fri, 21 Nov 2008 01:06:50 GMT91d46819-8472-40ad-a661-2c78acb4018c:9130799J.D. Meier's Blog<p>We posted our patterns &amp;amp; practices Reference Application Architecture Cheat Sheet on CodePlex .&amp;#160;</p>