Virtualization is a technique which allows multiple customers and organizations to share a single physical instance of a resource or an application. It is one of the most effective ways to reduce IT expenses while increasing efficiency and agility for all size business.

Hardware Virtualization/Server Virtualization

Server virtualization is the creation of a number of virtual instances of any operating system on a virtual platform. These operating systems are known as guest operating systems. There are 3 types of server virtualization.

• Full virtualization: Full virtualization using special software known as a hypervisor. Hypervisor or virtual machine monitor is a process that creates and runs virtual machines. It allows the host computer to run multiple guest VMs by virtually sharing its resources, like memory and processing.
• Paravirtualization:  Since every operating system receives information about the needs of other operating systems hosted on the same physical server, paravirtualization hypervisor manages guest operating systems that do not require large computational resources.
• OS-level Virtualization:  Involves altering the operating system in order to run different applications that can be operated by different users working on a single system at one time.

Network Virtualization

Network virtualization combines physical networking equipment and software network resources and network functionality into a single resource. It divides bandwidth into multiple, independent channels which can be assigned to servers and devices. There are two types of Network virtualization:

• Internal: A single system is provided with network-like functionality
• External: Many networks are combined into a virtual unit

Storage Virtualization

Storage virtualization, also known as cloud storage is the process of combining the physical storage from multiple storage devices so that it looks like a single storage device. There are two types of storage virtualization

• Block Level Storage: In block level storage raw volumes are created and each block can be used as an individual hard drive. Server based operating system controls these blocks and each block can be formatted with the required file system.
• File Level Storage: File level storage forms a logical pool of storage and enables users to use a logical path to access files.

Application Virtualization

Application virtualization can be abbreviated as ‘app virtualization’, i.e the separation of an installation from the client computer that is accessing it. It helps the user to use an application remotely from a server. The applications, executed on the virtual platform behave like it is directly interfacing with the original operating system. There are two types of application virtualization

• Remote application Virtualization: Remote applications run over a server. Through the remote control protocol, end users can view and interact with their applications on a network. The remote programs can be integrated completely with the user’s desktop so that they act like local applications, with the aid of technology known as seamless windows.
• Streaming application virtualization: Virtualized application is executed on the end-users local computer. When an application is requested, its components are directly fetched to the local computer on demand. Certain parts of the application are required in order to launch, rest can be downloaded in the background as needed. Once the download process is completed, a streamed application can function without any network connection.