Relation between WebSphere Portal Server and WebSphere Application Server?

Both WebSphere Portal Server and WebSphere Application Server are commonly used terms in Portal world. Following are some of key points that helps you understand the difference between the two commonly used terms.

 WebSphere Portal Server 

• It is nothing but an preloaded enterprise application (wps.ear) in integrated WAS.
• This application is dependent on database for storing application related information.
• It provides the all the features of portal i.e. personalization, customization, security etc.
• It's configuration and other personalization data is stored in form of database, XML and property files.
• It supports authorization of users.
• Performance measurement about pages / portlets is not measured in WebSphere Portal server.
• It only supports deployment of .war files.
• Only portlet applications can be deployed on WebSphere Portal server.

WAS(WebSphere Application Server) 

• It provides platform for WebSphere Portal Server.
• It doesn't depends on any database.
• Personalization is limited to each application deployed on the server.
• Configuration and related data is stored in form of XML and property files.
• Portal authentication is done in WAS.
• Performance measurement about pages / portlets can be measured in WAS.
• It supports deployment of both types of files (.war and .ear).
• One can develop either basic / advanced J2EE applications or using portlet container in WAS, one  can also develop and deploy portlet applications.