Abstract: Under the competitive and technology dependent global environment, modern technologies like Cloud Computing are keep boosting. Undoubtedly, enhancements of Cloud Computing are advancing their levels of productivity, profits and gaining market shares. As Cloud Computing already become popular throughout the glove and various peoples from different sectors are using Cloud Computing for different reasons therefore, it is now required to discuss insights of technology trends and developments for Cloud Computing in general. This paper mainly focuses on fundamental understanding of the different aspects of Cloud Computing such as an insight of Cloud Computing, different definitions, characteristics, deployment models, service models, key drivers and key challenges of Cloud Computing.