Amazon EC2

Amazon EC2 (Elastic Compute Cloud) is the virtual server service launched by Amazon in 2006 alongside Amazon S3, forming the foundational compute layer of Amazon Web Services. EC2 allows users to rent virtual machines — called instances — by the hour, with configurable CPU, memory, storage, and networking capacity.

The elasticity of EC2 — the ability to scale compute resources up or down in response to demand — was a departure from the traditional model of server provisioning, in which organizations purchased physical hardware with capacity planned for peak load. EC2 shifted the cost structure from capital expenditure to operational expenditure, and the operational model from capacity planning to elastic scaling.

EC2 did not merely virtualize servers. It virtualized the entire data center, turning a physical facility into an API call. The consequence was not just cost savings but a fundamental change in how software is architected: applications could be designed for failure, because the infrastructure beneath them could be replaced in seconds. This is the infrastructure that made microservices economically viable.