Liferay Portal can be installed through different methods depending on your specific needs. The installation options can be grouped into three main types:
Using an open source bundle: the bundles are the easiest and fastest installation method. They include an embedded database so all it takes to do the installation is to install a Java SE runtime environment, unzip, and run the bundle. It is recommended for people that want to review Liferay's functionality or for those who need to have Liferay working quickly.
Detailed installation procedure: explains how to install the portal in an existing application server or one that has been installed using vendor packages. This option is available for all the supported application servers. It is recommended for production environments and deployment to a proprietary app. server.
Using the ext environment: this option provides a full development environment to extend the functionality provided by Liferay. It is recommended for installation in the personal computers of developers doing the customization. It will not be covered in this guide. Refer to the developer guides for more information.
Liferay is provided in two editions so it is necessary to choose the one that better fits your specific needs. The reason they exist is because there are various opinions on the use of EJBs. With or without EJBs, we leverage our flexible Spring base architecture with the same code base.
Liferay Portal Enterprise: uses Enterprise Java Beans (EJB) and the services provided by them. This edition can only be deployed in full JavaEE applicaton servers.
Liferay Portal Professional: uses POJOs plus the functionalities provided by Spring and can be deployed in a servlet container.
Both editions provide the exact same functionality. The main reasons for choosing one over the other will come down to budget limitations or performance and reliability issues. To determine which edition is best for a specific case, it is necessary to perform tests that will simulate the real usage and load of the system.