Virtualization

In computing, virtualization is a big term that refers to the maximum use of computer resources.

One useful definition is a technique on which other systems, applications, or end users interact with those resources. This includes making a single physical resource such as a server, an operating system, an application, or storage device appear to function as multiple resources; or it can include making multiple physical resources such as storage devices or servers appear as a single resource.

Platform virtualization involves the simulation of computer environments.
Resource virtualization involves the simulation of combined, fragmented, or simplified resources.

Platform virtualization is performed on a given hardware platform by software which creates a simulated computer environment (a virtual machine) for its guest software. The guest software, which is often itself a complete operating system, runs just as if it were installed on a stand-alone hardware platform. Typically, many such virtual machines are simulated on a given physical machine. For the guest system to function, the simulation must be robust enough to support all the guest system's external interfaces, which may include hardware drivers.

There are several approaches to platform virtualization, listed below based on how complete a hardware simulation is implemented.

Emulation or simulation:

the virtual machine simulates the complete hardware, allowing an unmodified guest OS for a completely different CPU to be run. This approach has long been used to enable the creation of software for new processors before they were physically available. Examples include Bochs, PearPC, Power PC version of Virtual PC, QEMU without acceleration, and the Hercules emulator. Emulation is implemented using a variety of techniques, from state machines to the use of dynamic recompilation on a full virtualization platform.

Native virtualization and full virtualization:

the virtual machine simulates enough hardware to allow an unmodified guest OS to be run in isolation. Typically, many instances can be run at once. Examples include VirtualBox, Virtual Iron, Virtual PC, VMware Workstation, VMware Server (formerly GSX Server),VMware ESX Server, QEMU, Adeos, Mac-on-Linux, Win4BSD, Win4Lin Pro, and z/VM.

Virtual Drives

A virtual drive is a term used with respect to computers when a drive is emulated in some fashion. The drive being emulated could be a hard drive, floppy drive, CD/DVD or a network share among others.

A virtual hard drive can be created from RAM for fast read/write access.As well, there is software that makes one's Gmail account act as a virtual external drive.
Virtual DVDs are often mounted disk images via disk image emulator software. This allows one to read a CD or DVD from the disk image on a hard drive, rather than from a disc drive. This allows users to run software requiring the CD or DVD without having to swap discs, or even possess it.

Virtual burner

A virtual CD burner is a device driver that emulates a CD/DVD Burner. It appears as another drive in the system with writing capabilities. When information is written to the drive, it creates an ISO Image representation of the CD that would, under normal circumstances, be physically created.

This allows you to use any CD burning software to create what can be later mounted as a virtual drive.

Some Examples of Virtual CD/DVD Softwares are Virtual CD, Nero Image Drive , Alcohol, Daemon etc....

These software are very use full if you want to play games without the headache of maintaining the original CD/DVD. They can also be used for installing rapidly over network and usage as you don't have to manually go at each place and insert the CD'S to achieve your Target.

ThereFore Virtualization is very nessary and usefull in our daily life.....