Project References are a powerful way of expressing dependencies between your CDT projects, allowing you to write modular software built with CDT's managedbuild.
Two main pages control project references:
Project References Page under
Right click > Properties > C/C++ General > Paths and Symbols
Export Settings Page under
Right click > Properties > C/C++ General > Export Settings
If this page is missing, enable it under Window > Preferences > C/C++ > Property Page Settings
The export settings page gives you fine grained control of which paths, preprocessor symbols, and library files are exported by a given project's configuration.
When another project's configuration, in the workspace, references a configuration with exported settings, those settings are automatically propagated into the dependent project configuration. CDT also ensures that referenced projects are built as a prerequisite for building dependent projects.
This functionality prevents you from needing to maintain and update the build settings manually between all the dependent projects in your workspace. Simply configure the exported settings, setup the references, and the settings are propagated and kept in sync for you.