What are Middle-Tier Components in Oracle Application Server?

The middle tier is the part of an Oracle Application Server architecture that contains several components responsible for accepting requests from clients, validating the requests, and providing content, while using intelligent data caching for faster and reliable performance.

Some of the key components  in the Oracle Application Server middle tier are:

• Oracle Application Server Web Cache
  
• Oracle HTTP Server
  
• Oracle Application Server Containers for J2EE
  
• Oracle Portal Services