Preface – This post is part of the Cloud Computing series.

Introduction

Cloud computing has three types of service model, which includes Software-as-a-service (SaaS), Platform-as-a-service (PaaS), and Infrastructure as a service (IaaS). These service models approach and satisfy demands and secure benefits through resources. Companies offering these kinds of cloud computing services are called cloud providers.

Service Models of Cloud Computing

Software as a service (SaaS)

Software as a service is the on-demand delivery of applications that provides the user with access to cloud computing resources on a subscription basis. It removes the need to install and run applications on our computers or in the data centers, eliminating hardware and software maintenance expenses.

Characteristics of SaaS

• Elastic Infrastructure and highly scalable.
• End-users are not responsible for the management and updates of hardware and software. Applications get automatically updated.
• It has reduced the time spent on installation and configuration and the issues that can get in the way of software deployment.
• SaaS offers subscription-based billing of resources.

SaaS products provided by Google are Gmail, Google Drive, Google Docs, Google Planner, and Hangouts. Microsoft offers Microsoft editing tools, business email, communication, and documentation software.

Other Companies are Salesforce, Dropbox, ZenDesk, Cisco

Platform-as-a-Service

Platform as a service is a development and deployment model designed to support web life cycles like building, testing, deploying, and updating. It is a platform-based service where a third-party provider provides hardware and software tools for the development cycle. You only have to manage the application and services you develop, and the cloud service provider takes responsibility for everything else.

Characteristics of PaaS

• Platform as a service includes debugger, compiler, deploying, and managing code as a service for end-user. These development tools are offered together as a framework.
• In PaaS, all infrastructure components, such as storage and servers, are taken care of while developing and deploying applications.
• PaaS has control over security and privacy and can be customized.
• PaaS also offer the operating system with automatic updating to the latest versions.
• As PaaS is available via the Internet, employees can also access it through a remote location.

Platforms as a service include the Google App Engine, force.com, Windows Azure, and Apache.

Infrastructure as a Service

Infrastructure as a service is a cloud platform that offers computing services in a remote location via the Internet. Network architects mainly use IaaS. IaaS also provides access to resources such as virtual machines, virtual storage, etc.

Characteristics of IaaS

• IaaS supplies virtual disks for block-level storage of data. One virtual disk is mounted on another virtual machine at a given time; it can also be mounted onto numerous devices throughout its lifetime.
• Test and development type IaaS allows us to test at any scale and when required.
• Access is based on API (Application programming interface) and GUI (graphic user interface)
• Dynamic scaling of resources up and down to meet changing demand.

IaaS are Digital Ocean, Rackspace, Cisco Metapod, and Google Compute Engine(GCE).