[ros-users] Communicating between two user created packages

Dear all,

How can we communicate between two user created packages using a user created
ROS msg?
When I referred the tutorials, it only provides a scenario when the two
executables (publisher and listener) are in the same package.
Do we have to create the same msg in both the packages?
Also, I'm having trouble figuring out how to include headers from a user created
package to another package.


Any advise would be greatly appreciated, since I'm a beginner.

Thanks
Peshala