Solar cells convert the power of sunlight into electric energy. A solar cell has two primary functions: the generation of a photocurrent and the generation of a photovoltage to produce electric power. As a brief characterization of sunlight and basic electric parameters of solar cells, we pursue all the known techniques to test and characterize these cells. The essential characteristics of a solar cell are the short-circuit current (ISC), the open-circuit voltage (VOC), the fill factor (FF), and the solar energy conversion efficiency (η). Attention is paid to principal work with various kinds of load resistances, to the function of a pyranometer, a sun simulator, and the measurement of solar cells' quantum efficiency. We could measure the reflection and transmission of the cells. Electroluminescence, photoluminescence, and TLM measurements enlighten other aspects of solar cells. The importance of concentrated sunlight for increasing η is known. We are capable of fulfilling the measurement in this condition, also.