What are virtual machines?

I am very new to virtual computing. I have multiple vm's that interact with my MySQL database. The problem is that these virtual machines run program's in certain interval and are then inactive for a long time. I would like to know how to configure it...

Do you mean what type of hardware they use to run your virtual machines?

I am looking to run Linux virtual machines on Mac OS X. What are some recommendations for good open source VM's that are available?

I learned about Vagrant  from an article ( PHP: The Right Way ), I realized that I don't have an intuitive understanding of what the term "provisioning" means, and how it might be important to me as a web-developer.

Consider the operation of a machine shop in which there are M machines. These machines can be used to manufacture two different kinds of products, A and B. The total amount of product A manufactured by one machine in one week will be sold for a profit...

I'm running IIS on Windows 7 to test a website locally. How can I access my local site through my virtual machines? I'd like to test my website locally across multiple browsers before putting them into our staging environment. I have two virtual XP machines...

Right now I have a PC with an Intel core 2 6700 CPU, 4 GB RAM under windows XP and when I am running virtual machines(MS Virtual PC) it gets a bit slow. Sometimes I use several virtual machines, so I really need to upgrade my PC. Can anyone tell me what...

I would like to evaluate time spread between a large number virtual machines. Can I find this information within NTPd or is there a way to collect time drift on the client itself? I would like to emphasize that the machines in question are virtual machines...

Here is what I think. It's quite a long story. I remember the good old days when it was those fruit machines were you won 2ps. Then in early 2000s they brought out 10p machines where you could win up to £5 which was better like that Egyptian one...