Microsoft Transaction Server and Oracle database integration. The illustration is divided into three parts by vertical dotted lines.

On the left is Presentation in Tier One, which includes the client computer with Internet browser HTTP connections and LAN-based connections.

In the middle is Business Logic in Tier Two, which consists of mutiple Windows computers running Microsoft Transaction Server and Internet Information Server.

On the right is Data Elements in Tier Three, which consists of a computer running Windows NT/2000, Solaris, or another operating system with Oracle Server 8.0.6 or higher. Tiers Two and Three communicate through Oracle Net.