# What is Cloud Computing?

* Cloud computing is the on-demand delivery of compute power, database storage, applications, and other IT resources
* Through a cloud services platform with pay-as-you-go pricing
* You can provision exactly the right type and size of computing resources you need
* You can access as many resources as you need, almost instantly
* Simple way to access servers, storage, databases and a set of application services
* Amazon Web Services owns and maintains the network-connected hardware required for these application services, while you provision and use what you need via a web application.

## The Deployment Models of the Cloud

**Private Cloud:**

* Cloud services used by a single organization, not exposed to the public.
* Complete control
* Security for sensitive applications
* Meet specific business needs

**Public Cloud:**

* Cloud resources owned and operated by a thirdparty cloud service provider delivered over the Internet.
* Six Advantages of Cloud Computing

**Hybrid Cloud:**

* Keep some servers on premises and extend some capabilities to the Cloud
* Control over sensitive assets in your private infrastructure
* Flexibility and costeffectiveness of the public cloud

## The Five Characteristics of Cloud Computing

* **On-demand self service:**
  * Users can provision resources and use them without human interaction from the service provider
* **Broad network access:**
  * Resources available over the network, and can be accessed by diverse client platforms
* **Multi-tenancy and resource pooling:**
  * Multiple customers can share the same infrastructure and applications with security and privacy
  * Multiple customers are serviced from the same physical resources
* **Rapid elasticity and scalability:**
  * Automatically and quickly acquire and dispose resources when needed
  * Quickly and easily scale based on demand
* **Measured service:**
  * Usage is measured, users pay correctly for what they have used

## Six Advantages of Cloud Computing

* **Trade capital expense (CAPEX) for operational expense (OPEX)**
  * Pay On-Demand: don’t own hardware
  * Reduced Total Cost of Ownership (TCO) & Operational Expense (OPEX)
* **Benefit from massive economies of scale**
  * Prices are reduced as AWS is more efficient due to large scale
* **Stop guessing capacity**
  * Scale based on actual measured usage
* **Increase speed and agility**
* **Stop spending money running and maintaining data centers**
* **Go global in minutes:** leverage the AWS global infrastructure

## Problems solved by the Cloud

* **Flexibility:** change resource types when needed
* **Cost-Effectiveness:** pay as you go, for what you use
* **Scalability:** accommodate larger loads by making hardware stronger or adding additional nodes
* **Elasticity:** ability to scale out and scale-in when needed
* **High-availability and fault-tolerance:** build across data centers
* **Agility:** rapidly develop, test and launch software applications

## Types of Cloud Computing

* **Infrastructure as a Service (IaaS)**
  * Provide building blocks for cloud IT
  * Provides networking, computers, data storage space
  * Highest level of flexibility
  * Easy parallel with traditional on-premises IT
* **Platform as a Service (PaaS)**
  * Removes the need for your organization to manage the underlying infrastructure
  * Focus on the deployment and management of your applications
* **Software as a Service (SaaS)**
  * Completed product that is run and managed by the service provider

## Example of Cloud Computing Types

* **Infrastructure as a Service:**
  * Amazon EC2 (on AWS)
  * GCP, Azure, Rackspace, Digital Ocean, Linode
* Platform as a Service:
  * Elastic Beanstalk (on AWS)
  * Heroku, Google App Engine (GCP), Windows Azure (Microsoft)
* Software as a Service:
  * Many AWS services (ex: Rekognition for Machine Learning)
  * Google Apps (Gmail), Dropbox, Zoom

## Pricing of the Cloud – Quick Overview

* AWS has 3 pricing fundamentals, following the pay-as-you-go pricing model
* **Compute:**
  * Pay for compute time
* **Storage:**
  * Pay for data stored in the Cloud
* **Data transfer OUT of the Cloud:**
  * Data transfer IN is free
* Solves the expensive issue of traditional IT

## AWS Cloud Use Cases

* AWS enables you to build sophisticated, scalable applications
* Applicable to a diverse set of industries
* Use cases include
  * Enterprise IT, Backup & Storage, Big Data analytics
  * Website hosting, Mobile & Social Apps
  * Gaming

## AWS Global Infrastructure

* AWS Regions
* AWS Availability Zones
* AWS Data Centers
* AWS Edge Locations / Points of Presence
* <https://infrastructure.aws/>

## AWS Regions

* AWS has Regions all around the world
* Names can be us-east-1, eu-west-3…
* A region is a **cluster of data centers**
* **Most AWS services are region-scoped**

## How to choose an AWS Region?

If you need to launch a new application, where should you do it?

* **Compliance with data governance and legal requirements:** data never leaves a region without your explicit permission
* **Proximity to customers:** reduced latency
* **Available services within a Region:** new services and new features aren’t available in every Region
* **Pricing:** pricing varies region to region and is transparent in the service pricing page

## AWS Availability Zones

* Each region has many availability zones (usually 3, min is 2, max is 6). Example:
  * ap-southeast-2a
  * ap-southeast-2b
  * ap-southeast-2c
* Each availability zone (AZ) is one or more discrete data centers with redundant power, networking, and connectivity
* They’re separate from each other, so that they’re isolated from disasters
* They’re connected with high bandwidth, ultra-low latency networking

## AWS Points of Presence (Edge Locations)

* Amazon has 216 Points of Presence (205 Edge Locations & 11 Regional Caches) in 84 cities across 42 countries
* Content is delivered to end users with lower latency

## Tour of the AWS Console

* **AWS has Global Services:**
  * Identity and Access Management (IAM)
  * Route 53 (DNS service)
  * CloudFront (Content Delivery Network)
  * WAF (Web Application Firewall)
* **Most AWS services are Region-scoped:**
  * Amazon EC2 (Infrastructure as a Service)
  * Elastic Beanstalk (Platform as a Service)
  * Lambda (Function as a Service)
  * Rekognition (Software as a Service)
* **Region Table:** <https://aws.amazon.com/about-aws/global-infrastructure/regional-product-services>

## Shared Responsibility Model diagram

* CUSTOMER = RESPONSIBILITY FOR THE SECURITY **IN** THE CLOUD
* AWS = RESPONSIBILITY FOR THE SECURITY **OF** THE CLOUD