title: Explain the different tiers of 2 tier & 3 tier architecture?
body: <p>I am not able to understand which elements are called as first tier, second tier &amp; third tier &amp; where they reside. Can they reside on same machine or different machine. Which tier reside on which machine?  How we can identify a particular application as a 2 tier application or 3 tier application. Please explain with example</p>