Cloud Computing Basics

What is the cloud computing?

Simply put, cloud computing just means storing data and accessing computers over the internet. One can think of it as using somebody else’s computer temporarily. It has on-demand availability and does not require direct, active management by the user. We'll be referring to Amazon Web Services (AWS) as our public cloud provider for the rest of this document.

Six Advantages of Cloud Computing

1. Trade capital expense for variable expense – pay only when you need to use computing resources and pay only for what you use.
2. Benefit from massive economies of scale – using the cloud works out cheaper for the individual from a pay-as-you go standpoint. This is because a large number of customers use the cloud, and this usage is aggregated, consequently allowing AWS to achieve high economies of scale.
3. Stop guessing capacity – you can scale up or down as required, thereby using as much or as little capacity as is needed.
4. Increase speed and agility – resources can be made available very quickly and easily (in many cases, it’s just a click of a button away).
5. Stop spending money running and maintaining data centres – focus on the applications and the end-product, instead of worrying about maintenance of underlying structures.
6. Go global in minutes – applications can be deployed to multiple regions around the world easily.

Cloud Computing Service Models

1. Infrastructure as a Service (IaaS) – provides access to networking features, compute, and storage. IaaS has a high level of flexibility and management control regarding IT resources.
2. Platform as a Service (PaaS) – there’s no need to worry about managing the underlying infrastructure (hardware and/or software). All you need to be concerned with is the deployment and management of your application.
3. Software as a Service (SaaS) – this mostly refers to end-user applications. It’s a completed product that is run and managed by its service provider. An example would be Gmail.

Availability Zones and Regions

• An Availability Zone (AZ) consists of one or more discrete data centres, each with all the necessary resources, housed in separate facilities.
• An AWS Region is a physical location somewhere on the planet that consists of multiple Availability Zones.
• Edge Locations may or may not exist in a region. They are located within most major cities around the world. Edge Locations are specifically used by CloudFront (CDN) to distribute content to global users with low latency.