What is ec2?

Amazon EC2 (Elastic Compute Cloud) is a service that lets you rent virtual computers (called instances) in the cloud. You can choose the size, operating system, and how long you need them, and you pay only for what you use.

Let's break it down

  • Instance: A virtual server that runs your applications. Think of it like a laptop you can access over the internet.
  • Instance Types: Different sizes (CPU, memory, storage) for different workloads, e.g., t3.micro for small tasks, m5.large for general purpose, p4d for GPU‑heavy jobs.
  • AMI (Amazon Machine Image): A template that contains an OS and optional software, used to launch an instance.
  • Elasticity: You can start, stop, scale up or down, and terminate instances automatically based on demand.
  • Pricing Models: On‑Demand (pay per hour/second), Reserved (commit to 1‑3 years for a discount), Spot (bid for unused capacity at lower cost), and Savings Plans.

Why does it matter?

EC2 gives you the flexibility to run any software without buying physical hardware. It lets startups launch quickly, enterprises handle spikes in traffic, and developers test ideas without large upfront costs. The ability to scale automatically means you only use resources when you need them, saving money and improving performance.

Where is it used?

  • Hosting websites and web applications.
  • Running backend services, APIs, and microservices.
  • Big data processing, machine learning, and scientific simulations.
  • Game servers, media transcoding, and video streaming.
  • Development and testing environments for software teams.

Good things about it

  • Scalable: Add or remove capacity in minutes.
  • Pay‑as‑you‑go: Only pay for the compute you actually use.
  • Wide variety: Hundreds of instance types for any workload.
  • Global reach: Available in many regions, so you can place resources close to users.
  • Integration: Works seamlessly with other AWS services (S3, RDS, Lambda, etc.).

Not-so-good things

  • Cost complexity: Multiple pricing options can be confusing; forgetting to stop instances can lead to unexpected bills.
  • Management overhead: You still need to handle OS patches, security groups, and networking unless you use managed services.
  • Learning curve: Understanding instance types, AMIs, and scaling policies takes time.
  • Vendor lock‑in: Heavy reliance on AWS APIs can make moving to another cloud provider harder.
  • Performance variability: Spot instances and shared hardware can sometimes have inconsistent performance.