AWS and cloud computing basics
A crash-course section for AWS beginners. Networking basics (clients, servers, IPs, routers, switches) are covered far deeper in my CCNA notes, so this sticks to the cloud parts.
Why cloud
Traditional IT means renting a data center, paying for power, cooling, and maintenance, waiting weeks for hardware, staffing it 24/7, and praying about earthquakes.
Cloud computing is on-demand delivery of compute, storage, database, and other IT resources, pay as you go: provision exactly what you need almost instantly. AWS owns the hardware; you rent slices via a web console.
Deployment models
- Private: cloud tech operated for one org. Full control, sensitive workloads.
- Public: provider-owned resources delivered over the internet (AWS, Azure, GCP).
- Hybrid: some servers stay on-prem, some capabilities extend to the cloud.
Five characteristics
On-demand self service, broad network access, multi-tenancy and resource pooling, rapid elasticity and scalability, measured service (pay for what you use).
Six advantages
Trade CAPEX for OPEX, benefit from massive economies of scale, stop guessing capacity, increase speed and agility, stop paying to run data centers, go global in minutes.
Service models
- IaaS: you manage apps, data, runtime, OS. EC2, Digital Ocean.
- PaaS: you manage apps and data only. Elastic Beanstalk, Heroku.
- SaaS: you just use it. Rekognition, Gmail, Zoom.
Pricing fundamentals
Pay for compute time, pay for stored data, pay for data transfer out. Transfer in is free.
Global infrastructure
A region is a cluster of data centers (us-east-1), and most services are region-scoped. Pick by compliance, latency to users, service availability, and price (which varies per region).
An Availability Zone is one or more discrete data centers with redundant power and networking: typically a minimum of 3 per region, isolated from each other but linked by low-latency fiber. Build across AZs for high availability.
Edge locations (points of presence): 400+ in 90+ cities for low-latency content delivery.
Global services: IAM, Route 53, CloudFront, WAF. Region-scoped: EC2, Beanstalk, Lambda, Rekognition.
Shared responsibility
AWS secures the cloud (hardware, facilities, managed service infrastructure); you secure what’s in the cloud (your data, access controls, configuration).
This comes back with specifics in the security post.