Configuring multiple portals on the same Liferay server

We created our portal for CIGNEX Neighborhood. Now, imagine that we get a requirement to create a Liferay Neighborhood portal. We need to then install another Liferay server and configure it, right? Is there any other way? Yes, we can also use our existing Liferay server to configure another portal which does not share any of the CIGNEX Neighborhood portal information. Without using a separate database, application server/servlet container, and other resources, we can easily set up another portal on Liferay.