There are four phases that basically gets involved in the cloud architecture:

1. Launch phase: it launches the basic services and makes the system ready for communication and for application building

2. Monitor phase: it monitors the services that is being launched and then manages them so that on demand the user will be able to get what he wants.

3. Shutdown phase: it shutdown the services that are not required first and after all the services gets shutdown, and then it closes the system services. 

4. Cleanup phase: it clean up the left out processes and services that is being either broken or didn’t get shutdown correctly.

1. Zero infrastructure investment : Cloud architecture provide user to build large scale system with full hardware, machines, routers, backup and other components. So, it reduces the startup cost of the business. 

2. Just-in-time Infrastructure : It is very important to scale the infrastructure as the demand rises. This can be done by taking cloud architecture and developing the application in the cloud with dynamic capacity management. 

3. More efficient resource utilization : Cloud architecture provides users to use their hardware and resource more efficiently and utilize it in a better way. This can be done only by applications request and relinquish resources only when it is needed (on-demand).

- Cloud architecture uses simple APIs to provide easily accessible services to the user through the internet medium. 

- It provides scale on demand feature to increase the industrial strength. 

- It provides the transparency between the machines so that users don’t have to worry about their data. Users can just perform the functionality without even knowing the complex logics implemented in cloud architecture.

- It provides highest optimization and utilization in the cloud platform

It depends on the type of business that demands a cloud setup. Suppose if the subscription on a public cloud for an application that is to be deployed on OS images is proving to be more costly then to buy some new datacenters and maintain them. Then obviously the a private cloud has to be setup instead of a public cloud. This public clouds follow utility billing methodology as electricity bill for example.

The hypervisor is a virtual machine monitor (VMM) that manages resources for virtual machines. The name hypervisor is suggested as it is a supervisory tool for the virtual machines. There are mainly two types of hypervisors :

- Type-1: the guest Vm runs directly over the host hardware, e.g Xen, Hyper-V, VmWare ESXi

- Type-2: the guest Vm runs over hardware through a host OS, e.g Kvm, Oracle virtualbox

Eucalyptus stands for “Elastic Utility Computing Architecture for Linking Your Programs to Useful Systems” and provides an open source software infrastructure to implement clusters in cloud computing platform. It is used to build private, public and hybrid clouds. It can also produce your own datacenter into a private cloud and allow you to extend the functionality to many other organizations. Eucalyptus provides APIs to be used with the web services to cope up with the demand of resources used in the private clouds.

Cloud computing platform has various databases that are in support. The open source databases that are developed to support it is as follows:

- MongoDB: is an open source database system which is schema free and document oriented database. It is written in C++ and provides tables and high storage space. 

- CouchDB: is an open source database system based on Apache server and used to store the data efficiently

- LucidDB: is the database made in Java/C++ for data warehousing. It provides features and functionalities to maintain data warehouse.

The security laws which are implements to secure data in the cloud are as follows:

- Input validation : controls the input data which is being to any system.

- Processing  : control that the data is being processed correctly and completely in an application.

- File : control the data being manipulated in any type of file.

- Output reconciliation : control the data that has to be reconciled from input to output.

- Backup and recovery: control the security breaches logs and the problems which has occurred while creating the back.