Cloud computing models can be categorized into three types: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). IaaS provides basic storage and computing capabilities over the network. PaaS provides computing platforms including operating systems and programming languages. SaaS provides access to application services installed on servers without needing to worry about installation, maintenance, or coding. Common examples of each include Amazon EC2 for IaaS, Google App Engine for PaaS, and Gmail for SaaS.

1. CLOUD
COM
PUTING
M
ODELS

2. CLOUD COMPUTING MODELS
Cloud Providers offer services that can be grouped into three categories
1.IaaS : Infrastructure as a Service .
2.PaaS :Platform as a Service .
3.SaaS :Software as a Service

3. INFRASTRUCTURE AS A SERVICE “IAAS”
Infrastructure as a Service (Iaas):
IaaS provides basic storage and computing capabilities as standardized
services over the network. Servers, storage systems, networking
equipment, data centre space etc
The customer would typically deploy his own software on the infrastructure.
Some common examples are Amazon, GoGrid, 3 Tera, etc.
IaaS Examples:
Amazon Web Services (AWS), Google Compute Engine (GCE), Joyent.
IaaS Use-Case: Extends current data center infrastructure for temporary
workloads

4. INFRASTRUCTURE AS A SERVICE “IAAS”

5. PLATFORM AS A SERVICE “PAAS“
Platformas a Service (Paas):
PaaS provides you computing platforms which typically includes operating
system, programming language execution environment, database, web
server.
technically It is a layer on top of IaaS as the second thing you demand
after Infrastructure is platform. .
PaaS Examples:
AWS Elastic Beanstalk, Windows Azure, Heroku, Force.com, Google App
Engine, Apache Stratos.

6. PLATFORM AS A SERVICE “PAAS“

7. SOFTWARE AS A SERVICE “SAAS“
Software a Service (Saas):
In a SaaS you are provided access to application services installed at a
server. You don't have to worry about installation, maintenance or
coding of that software. You can access and operate the software with
just your browser. You don't have to download or install any kind of
setup or OS, the software is just available for you to access and operate.
The software maintenance or setup or help will be provided by SaaS
provider company and you will only have to pay for your usage. .
SaaS Examples:
Google Apps, Microsoft office365, Google docs, Gmail, WHMCS billing
software

8. SOFTWARE AS A SERVICE “SAAS“