Cloud testing, or cloud-based testing, is a method used to evaluate web applications for scalability, performance, security, and reliability using third-party cloud computing environments, which provide the necessary infrastructure for testing. This approach offers distinct advantages over on-premise testing, such as eliminating environment-related delays and reducing costs due to a 'pay-as-you-go' model, making it a scalable and economical option for businesses of all sizes. Cloud testing supports automated functional and non-functional testing types, including system, interoperability, performance, availability, multi-tenancy, security, disaster recovery, and browser performance testing. A case study highlights how a tech startup, initially constrained by limited infrastructure, enhanced its testing capabilities and efficiency by adopting cloud-based testing tools, leading to improved test coverage and product quality. LambdaTest is cited as a cloud-based testing platform that allows users to conduct cross-browser testing across numerous combinations, leveraging parallel execution to expedite testing processes.