What is cloud computing?

Let's understand the term of cloud computing

What is Cloud Computing?

• Cloud Computing is the on-demand (You get it when you need it) 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 service, while you provision and use what you need via a web application.

The Deployment Models of the Cloud

1. Private Cloud :

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

2. Public Cloud : -> Cloud resources owned and operated by a third-party cloud services provider over the internet. -> six advantages of cloud computing. => google cloud, azure, AWS for example.

3. Hybrid Cloud : -> Keep some servers on premises and extend some capabilities to the cloud -> Control over sensitive assets in your private infrastructure -> Flexibility and cost-effectiveness of the public cloud => Using on-premise servers and at the same times the cloud.

The 5 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 many different client platforms

• Multi-tenancy and resource pooling -> Multiple customers can share the same infrastructure and applications with security and privacy and they are serviced from the same physical resources

• Rapid elasticity and scalability -> Automatically and quickly get and give resources when needed and 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) -> You don't own hardware you going to pay on-demand ->Reduced TOTAL COST OF OWNERSHIP '(TCO)' & Operational Expense '(OPEX)' => You don't buy the hardware in advance you are going to rent it from AWS.

• 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 =>Before, we used to buy hardware and pray that they will meet the required capacity.

• Increase speed and agility ->We can create operate, and do stuff right away no blockers for us to be efficient

• 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

• Hight-availability and fault-tolerance: build across data centers

• agility: rapidly develop, test and launch software applications.

Type 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 => Examples : Amazon EC2 GCP, Azure, Rackspace, Digital Ocean, Linode

• 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 => Examples : Elastic Beanstalk Heroku, Google App Engine, Windows Azure.

• Software as a Service (SaaS) -> Completed product that is run and managed by the service provider => Examples : Many AWS services Google apps, dropbox, zoom..

Below, you will find the difference between the type of cloud computing

Pricing of the Cloud

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 multi-different set of industries

• Use cases include : -> Enterprise IT, Backup & Storage, Big Data analytics -> Website hosting, Mobile & Social Apps -> Gaming

AWS Global Infrastructure

1. 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? -> Depends on 1- Compliance : Data governance and legal requirements 2- Proximity : reduced latency 3-Avaible services : new services and new features aren't available in every regions 4-Pricing ; pricing varies region to region.

2. AWS Availability Zones : -> Each region has many availability zones -> each AZ is one or more discrete data centers -> they're separate from each other, so that they're isolated from disasters -> They're connected wit high bandwidth, ultra-low latency networking

3. AWS Data Centers

4. AWS Edge Locations / Points of Presence -> Amazon has more than 216 PoP (205 Edge locations & 11 Regional caches)

Shared Responsibility Model diagram

-> Customer = Responsibility for the security IN the could -> AWS = Responsibility for the security OF the cloud