From the course: Learning Virtualization

Overview of virtualization

From the course: Learning Virtualization

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Overview of virtualization

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- [Instructor] I'd like to start off with a basic definition of what virtualization is. Let's get a working definition under our belt. A dictionary definition of the word virtual is: "Very close to being something without actually being it." And we will find when we create virtual machines and virtual servers that we create something that is very close to an actual computer without actually being a computer. Another dictionary definition is: "Being such in power or effect though, not actually such." And this is one of the goals of our virtual machines, to have the same power and effect as a physical machine, though they are not actually a physical machine. Continuing to define the word virtual and now more in computer terms, virtual is the opposite of physical. And in the common terminology these days amongst engineers when you want to discuss a machine that is not virtual, you say it's a physical server. These virtual servers exist only in the memory of a computer. There are no physical components for us to touch or see, it exists only in memory. Let's look at a metaphor of other virtual items and then compare that to virtual servers. In a car racing video game, there is no physical car. We have only a computer simulation of an engine, a transmission, brakes, tires and other parts that combine to form a virtual car. Likewise, when we have a virtual server, there are no physical computer parts. We're not going to buy a physical hard drive or memory or processor. Instead, we will have a computer simulation of a processor, memory, disk, and network. In particular, if we were hoping to build an email server, we could go out and buy physical parts and combine those parts into a physical computer. Or we could use virtualization software to create a simulation of a processor, memory and disk and use those virtualized components to create a virtual server. That virtual email server would be able to send and receive email exactly the same as a physical email server, and therefore it accomplishes the same goals as a physical server. That's one of the common themes of our virtual servers, they will accomplish the same task in the same way as a physical server would, but instead they will be virtual servers.

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