This review discusses recent results on coronal heating and structuring related to observations made with coronal observatories of the last generation, e.g. SOHO, TRACE and Yohkoh. The topics include: inferring the three-dimensional spatial structure of the corona in slowly changing active regions, deriving the frequency of microflares vs. their total energy, using accurate models to interpret observations. Accurate models are required because the dynamics and energy balance of the coronal plasma involve several physical effects of comparable importance and some of them are non-linear. In this respect the paper presents the detailed modeling of a loop brightening, observed with TRACE at high temporal and spatial resolution, by means of a hydrodynamic model of magnetically confined coronal plasma. The model and the high quality observations allow us to infer the location and the distribution of the heating inside the loop, as well as its evolution.