Symplectic geometry is an even dimensional geometry that lives on even dimensional spaces and measures two dimensional quantities rather than the one dimensional quantities like lengths and angles familiar from Riemannian geometry. Moreover, symplectic geometry displays an intriguing interplay between rigidity and flabbiness, which makes the question of constructing invariants that distinguish between between different symplectic structures especially interesting. In this talk we shall explore some of these aspects and motivate the definition of a certain symplectic invariant, namely the symplectic capacity.