Day 1 What is Cloud Computing

What is Cloud Computing? (IaaS, PaaS, SaaS)

Cloud computing is the delivery of various services—such as servers, storage, databases, networking, software, and analytics—over the internet (the "cloud") to offer faster innovation, flexible resources, and economies of scale. Instead of owning and maintaining physical servers or data centers, organizations can rent access to storage, compute power, and other cloud resources.

Cloud computing is typically categorized into three primary models:

1. Infrastructure as a Service (IaaS):

   • IaaS provides virtualized computing resources over the internet, such as virtual machines, storage, and networking. It offers users the fundamental infrastructure on-demand while giving them control over the operating system, applications, and middleware.

   • Example: Amazon EC2, Microsoft Azure Virtual Machines, Google Compute Engine.

2. Platform as a Service (PaaS):

   • PaaS provides a platform that allows users to build, deploy, and manage applications without worrying about the underlying infrastructure. This model simplifies the development and deployment process by handling operating systems, databases, and runtime environments.

   • Example: AWS Elastic Beanstalk, Google App Engine, Microsoft Azure App Services.

3. Software as a Service (SaaS):

   • SaaS delivers fully functional, user-facing software applications over the internet. The cloud provider handles everything, including the application, runtime, data, and infrastructure. Users access the software through web browsers or apps.

   • Example: Gmail, Salesforce, Office 365, Dropbox.

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Benefits of AWS Cloud

1. Cost-Effective:

   • AWS offers a pay-as-you-go pricing model, which allows you to only pay for the resources you use without upfront investments. This helps reduce the costs associated with purchasing and maintaining physical servers.

2. Scalability:

   • AWS services are highly scalable, enabling you to adjust resources dynamically as demand changes. Whether you're running a small workload or enterprise-scale applications, AWS allows you to scale horizontally (more servers) or vertically (bigger servers) to meet your needs.

3. Flexibility and Agility:

   • AWS provides a wide range of services that let you choose the tools and languages that work best for your project. It offers quick deployment and flexibility to pivot your business needs, helping businesses innovate faster.

4. Global Reach:

   • With its extensive global infrastructure, AWS allows you to deploy applications close to your users to reduce latency. AWS also provides multi-region redundancy, enabling high availability.

5. Security:

   • AWS follows stringent security measures, including physical data center security, encryption, compliance certifications (such as ISO, PCI DSS), and features like IAM (Identity and Access Management) to control access.

6. Reliability:

   • AWS ensures high availability by offering services like Amazon S3 and Amazon RDS with built-in redundancy. With services like auto-scaling and load balancing, AWS provides reliable infrastructure for mission-critical workloads.

7. Managed Services:

   • AWS provides managed services like RDS, Elastic Beanstalk, and Lambda, taking care of the underlying infrastructure management, allowing developers to focus on building applications.

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AWS Global Infrastructure

AWS operates one of the most comprehensive global cloud infrastructures, which consists of Regions, Availability Zones, and Edge Locations.

1. Regions:

   • A Region is a physical location in the world where AWS has multiple data centers. Each region consists of multiple Availability Zones and is isolated from other regions to ensure high availability and fault tolerance.

   • Example regions include US East (N. Virginia), EU (Frankfurt), and Asia Pacific (Singapore).

2. Availability Zones (AZs):

   • An Availability Zone is a data center or group of data centers located within a region that operates independently but is connected with other AZs in the same region through low-latency links. Availability Zones are designed for fault isolation, ensuring that a failure in one AZ does not affect others in the same region.

   • AWS typically offers 2-6 AZs per region, allowing applications to achieve higher availability and fault tolerance by spreading resources across AZs.

3. Edge Locations:

   • Edge Locations are data centers that host Amazon CloudFront content delivery networks (CDNs). These locations are closer to end-users, allowing them to cache frequently accessed content (like websites and applications) to reduce latency.

   • AWS has hundreds of edge locations worldwide, enabling faster content delivery to users in various regions.