Basics of Cloud Computing: IaaS,SaaS and PaaS
As per Wikipedia Cloud Computing is “Internet-Based Computing that Provides Shared Computer Processing Resources on Demand”.
Cloud Computing has been divided into three broad categories : IaaS , PaaS and SaaS.
A) IaaS stands for Infrastructure as a Service, involves hardware and software combinations to build everything on your own. Three main part of computing i.e. CPU, Memory and Disk can be rented/provisioned on the cloud. Example of IaaS is Amazon’s S3, Google Compute Engine, Oracle Storage Cloud, or Oracle Bare Metal Cloud
B) PaaS stands for Platform as a Service, involves tools and services to develop and deploy applications. Example of PaaS are Google App Engine, Java Cloud Service, Database as a Service, etc
C) SaaS stands for Software as a Service, involves a ready-made applications to be used by its end-users. Example of SaaS are Gmail, DropBox, Oracle Fusion Applications, SalesForce, Workday etc
Characteristics/Benefits of Cloud:
• On-Demand & Self Service hence services can be provisioned quickly
• Pay as You Go: Services are Measured and Metered that pay for what you use.
• Multi-Tenancy : Assume living in one of many Flats in Big Building as rented space
• Secure: Against all myths, Cloud Computing is more secure as cloud computing companies spend lot of money to ensure Data is safe
• Reliable: Cloud vendors provide highly available computing
• Scalable: Easily extendible or scalable as your demand increases
Deployment Models for Cloud:
• Public Cloud : Services are rendered over a network that is open for Public Use.
• Private Cloud : Cloud infrastructure operated solely for a single Organization.
• Hybrid Cloud : composition of private and public usually a composition of services some form private cloud while others from Public Cloud.
• Community : similar to private cloud but extended to small community like serving all Public Departments in England i.e. Police, Fire Brigade, Hospitals