In general, a web portal represents a web application that provides a single POINT of access to variety of information. 

Functionality of a portal can extended very easily by creating custom applications that can run inside a portal. These applications are called portlets. 

For running portlets you need application server that can run a portlet container spec (JSR168 or JSR286). There are dozens of free and enterprise portal products available. 

Liferay portal is an open source portal and below are the benefits of using Liferay portal: 

• Content management system(Documents, Articles).
• 2-stage,3-stage workflows and publishing.
• SOCIAL networking. 4)Sites and organization basis pages.
• Integration with third party like LDAP, Solr, SSO(CAS, Siteminder).
• Portlets realted to Wiki's, News, Finance, Social, Workflow, Collaboration.
• Compatible with different Operating systems, databases and APP SERVERS.
• Compatible with UI technologies and web services.
• Compatible with different scripts like PHP, Ruby, Grails, Python.
• Suppport of HOT deployment feature.

In general, a web portal represents a web application that provides a single point of access to variety of information. 

Functionality of a portal can extended very easily by creating custom applications that can run inside a portal. These applications are called portlets. 

For running portlets you need application server that can run a portlet container spec (JSR168 or JSR286). There are dozens of free and enterprise portal products available. 

Liferay portal is an open source portal and below are the benefits of using Liferay portal: