Solar behavior is a very complicate mixture of coupled non-linear
processes of different spatial and temporal scales. Recent advances
in solar observations, theory and numerical simulations expanded our
understanding of how the Sun works, and at the same time opened new
challenges. In this talk I will review various aspects of
manifestation of solar magnetic activity on different scales, from
solar cycle modulations and their connections to dynamo models to
problems of self-organization and small-scale dynamics of the solar
convection.