The "planning" term should be read the same way as "estate planning" or "financial planning." They're a charity, so they have employees dedicated to ensuring a continuous stream of donations. For example, someone might pledge to give $X over the next 10 years, or to give a percentage of their estate to the foundation when they die.

This branch of the company is often called "development," but R&D organizations sometimes need to come up with different names because that term gets overloaded.