What does the Adaptive Options mean in ANSYS HFSS Analysis Setup?

HFSS analysis setup provides 3 different options to control the adaptive solution of a model that contains 3D component.

If the design contains 3D components, the Adaptive Options tab lets you select 3D Component Adapt Options. Parallel component adapt for mesh fusion workflow in MCAD including both 3D component array and general mesh fusion. During the component adapt, the multiple components are solved in parallel during each adaptive pass. You can select from 1) Fully Independent adapt (the default for a Mesh Fusion project), 2) Balanced adapt, and 3) Fully coupled adapt. If you select Fully Independent or Balanced, you can specify that the last adaptive solve performs a Fully Coupled Solve, or if unchecked, a memory estimation.