A photovoltaic array is a linked collection of photovoltaic modules, which are in turn made of multiple interconnected solar cells. This chapter devoted mainly for various combination of solar cell and PV module for a given rated capacity. The theory and construction of PV array along with rigid and flexible thin film modules are presented. Effects of packing factor, cell configurations, different connections between cell and modules, efficiency of array are also presented with the help of solved examples. Different applications and performances of PV system have also discussed. Series and parallel combination, balance of the system, shading effect, Maximum power point tracker (MPPT) are also discussed.