Amazon Web Services (AWS) is a cloud computing platform that offers computing resources and services on a pay-as-you-go basis, allowing users to replace upfront infrastructure costs with lower variable costs that scale with usage. Key AWS services include Amazon EC2 for compute power and Amazon S3 for storage. AWS provides benefits like low costs through pay-as-you-go pricing, instant scalability, flexibility, security, and opportunities for freshers to work on emerging cloud technologies.