Two parts to a big question, "What is Analysis And Design"?
Analysis aka the first question of the collective two.
An activity or a rhetorical strategy, to separate the parts of a whole and examine each part.
An investigation of the component parts of a whole and their relations in making up the whole.
Design aka the second question of the collective two.
Purpose: an anticipated outcome that is intended or that guides your planned actions.
Design something for a specific role or purpose or effect.