Amazon Web Services (AWS) is a subsidiary of Amazon providing on-demand cloud computing platforms and APIs to individuals, companies, and governments. AWS generates revenue through a pay-as-you-go model, offering services such as computing power, storage, and databases. Launched in 2006, AWS has grown to dominate the cloud market, with significant milestones including the introduction of Amazon S3 and Amazon EC2. Candidates should be aware of AWS's continuous innovation and its pivotal role in driving Amazon's profitability.