Cloud computing, led by major providers like AWS, Azure, and GCP, has revolutionized IT by delivering IaaS, PaaS, and SaaS to businesses, reshaping digital strategies across industries. The core attributes of scalability, cost efficiency, and accessibility make cloud computing a cornerstone for operational efficiency and innovation. The layered cloud model (IaaS, PaaS, and SaaS) allows tailored adoption and scalability. Public clouds offer cost-effective shared infrastructure, private clouds provide exclusivity and control, while hybrid clouds seamlessly integrate both for flexibility. Community clouds suit collaborative needs with shared concerns like security. Open-source solutions, including OpenStack, Apache CloudStack, and Eucalyptus, empower cloud management with diverse language support. Optimization becomes paramount in enhancing cloud efficiency, aligning resource utilization with a pay-as-you-go model. Optimization metrics span IaaS, PaaS, and SaaS layers, covering makespan, execution time, resource utilization, cost efficiency, and reliability. Techniques like metaheuristic algorithms, machine learning, and hybrid approaches contribute to efficient cloud workflow scheduling. In conclusion, optimization is pivotal for unlocking the full potential of cloud computing, ensuring a harmonious balance between cost-effectiveness, performance enhancement, and environmental sustainability. As cloud computing continues to evolve, embracing trends and optimizing workflows through innovative techniques becomes imperative for businesses seeking a competitive edge in the dynamic digital landscape.