What is Cloud Computing?
Why Interviewers Ask This
This question tests conceptual clarity. Interviewers want to hear a precise, confident definition before moving to more complex AWS / Cloud Computing topics. It also reveals how well you can explain technical ideas to non-experts.
Answer
Cloud computing is the delivery of computing services — servers, storage, databases, networking, software, analytics, and intelligence — over the internet ("the cloud") to offer faster innovation, flexible resources, and economies of scale. Instead of owning and maintaining physical data centers and servers, you access technology services on an as-needed basis from a cloud provider and pay only for what you use. Key characteristics (NIST definition): (1) On-demand self-service: provision resources without human interaction with the provider; (2) Broad network access: available over the network via standard mechanisms; (3) Resource pooling: provider serves multiple customers using a multi-tenant model; (4) Rapid elasticity: scale up or down quickly and automatically; (5) Measured service: pay for what you use (metering). Service models: IaaS (Infrastructure as a Service — EC2), PaaS (Platform as a Service — Elastic Beanstalk, Heroku), SaaS (Software as a Service — Gmail, Salesforce). Deployment models: Public cloud (AWS, Azure, GCP), Private cloud (on-premises), Hybrid cloud (both), Multi-cloud (multiple public providers). Major providers: Amazon Web Services (AWS — market leader ~33%), Microsoft Azure (~22%), Google Cloud Platform (~10%), Alibaba Cloud.
Common Mistake
A common mistake is memorizing definitions without understanding implications. When asked this question, go one level deeper — explain what happens when this concept is misused or ignored.