Project baselines are versions of the schedule part of the project plan ie typically they would have tasks, resources, assignments and ETC's and actuals for those which can also have monetary values. Baselines serve as snapshots a give points of time to monitor scheduled progress.
Financial plans may be based on resource assignments or allocations or they can be manually created. Even if they come from the resource assignments they are not automatically updated. Only the actuals may be updated from the PPA_WIP if they are posted to WIP.
Financial plans serve for mored versatile planning and monitoring project financial data grouped in different ways to suit the needs of the watch dogs for money.
If you look at the ER digragms in the Tech Ref you can see how the baselines and financial plans relate to investments and to each other.
Martti K.