The project may have many components or applications. The developer use common classes, resources and libraries using jars. Suppose think when we in developing stages we need to change some class more frequently. Then we need to open resource project and build your jar and add this to your current project. Net beans support facility to add project to project features. Netbeans automatically build dependent jar for you.See my example project
The Basic project contains some basic classes and interfaces. The Application Project contains application classes and basic project added to it as well as Web Application
“com.lanka” project is the Basic project
“com.lanka.app” prject is the application project
“com.lanka.web” project is the web project.
Application and web project need Basic project.
Netbeans automatically build dependent jar for you.