Cloud Computing

Cloud computing is the model of delivering compute, storage, networking, and software as on-demand services over the internet, billed by usage rather than by capital purchase. Cloud providers operate the underlying hardware and abstract it behind APIs, so customers consume resources elastically without managing data centres.

Service models

• IaaS (Infrastructure as a Service). Virtual machines, storage, networking. AWS EC2, Google Compute Engine, Azure VMs.
• PaaS (Platform as a Service). Runtimes and managed databases on top of IaaS. AWS Beanstalk, Heroku, Google App Engine, Render, Railway.
• SaaS (Software as a Service). Finished applications consumed over the internet. Gmail, Slack, Salesforce.
• FaaS / Serverless. Functions executed on demand, with no server management. AWS Lambda, Cloudflare Workers, Google Cloud Functions.

Deployment models

• Public cloud. Multi-tenant infrastructure owned by a hyperscaler.
• Private cloud. Cloud-style infrastructure dedicated to one organization, on-prem or hosted.
• Hybrid cloud. Workloads split or moving between public and private.
• Multi-cloud. Workloads distributed across more than one public provider.

Major providers

• AWS, Microsoft Azure, Google Cloud, Oracle Cloud, IBM Cloud, Alibaba Cloud, Tencent Cloud, DigitalOcean, Linode (Akamai), Cloudflare