Saving Function describes relationship between disposable income and saving. Form: S = -a + (1-b)Y = -a + sY, where S is saving, a is autonomous consumption (negative of which is autonomous dissaving), s is MPS. MPS: Typically 0 to 1; fraction of additional income saved. Inverse relationship with MPC: MPS = 1 - MPC. APS (Average Propensity to Save): S/Y; increases with income (higher-income groups save higher proportion). Saving motives: Precautionary (emergencies), Speculative (investment opportunities), Intertemporal (future consumption), Wealth accumulation. Determinants of saving: Income level (primary), Interest rates (higher rates encourage saving), Expectations (uncertain future increases saving), Liquidity (access to credit affects saving), Life-cycle factors (youth borrow, middle-age save, retirement dissave). Graphically: Saving function upward-sloping, with negative intercept (negative saving at zero income). Relationship with consumption: At income where C = Y, saving is zero; below that income, dissaving occurs. Indian context: Low national saving rates despite high income growth; increasing saving rate with financial inclusion. ICAI focus: MPS/APS relationships, determinants, policy effects. Exam tip: "At equilibrium income, saving = investment"; changes in saving affect consumption and investment.