1. Infrastructure as a Service (IaaS)
2. Platform as a Service (PaaS)
3. Software as a Service (SaaS)
4. Function as a Service (FaaS)

Infrastructure as a Service (Iaas) is a cloud computing model that provides virtualized computing resources over the internet. It provides scalable and on-demand access to essential IT components such as Virtual Machines (VMs) Storage, and networking resources without the need to invest in hardware.

• Virtual Machines (VMs): emulate physical servers (for example Amazon EC2)
• Storage: (for example Amazon S3: Simple Storage Service)
  • Object storage
  • Block storage
  • File storage
• Networking:
  • Virtual Networks
  • Subnets
  • Load Balancers
  • VPN connections

Platform as a Service (PaaS) provides a platform allowing customers to develop, run, and manage applications without encountering the complexity of building and maintaining the underlying infrastructure.

In other words, PaaS offers a ready-made environment for developers to focus solely on coding and deploying applications rather than worrying about hardware provisioning, operating system updates, or network configuration.

PaaS platforms typically provide a range of development tools, middleware, and runtime environments and allow developers to choose the tools and technologies that best suit their needs. AWS Elastic Beanstalk:

• Elastic Beanstalk: Amazon Web Services (AWS) offers Elastic Beanstalk as a PaaS solution for deploying and managing web applications and services. With Elastic Beanstalk, developers can upload their application code, and AWS automatically handles the deployment, scaling, load balancing, and monitoring aspects, which simplifies the deployment process.

Software as a Service (SaaS) delivers software applications over the internet on a subscription basis. In the SaaS model, the software is hosted and maintained by a third-party provider, which eliminates the need for users to install, manage, or update the software locally on their devices. Instead, users can access the software through a web browser or application interface, typically paying a monthly or annual fee for usage.

SaaS Examples:

Functions as a Service (FaaS): commonly known as serverless computing, is a model where developers focus entirely on writing code, while the cloud provider automatically handles the underlying infrastructure, scaling, and availability. With FaaS, you deploy individual functions that are triggered by events such as a file upload, a database update, or an API call.

Benefits of FaaS include:

• No Server Management
• Automatic Scaling
• Cost Efficiency

AWS's FaaS Solutiun is called AWS Lambda.