What are virtual machines?

What are virtual machines used for?

• What is the purpose of virtual machines like VM WARE? What are some reasons to use virtual machines?

• Answer:

  This is certainly not an exhaustive list/answer, just what I have used them for in the past. Ever need to try something on a Linux machine from your Windows computer, but didn't have any access to a remote Linux machine via SSH? Kick off a Linux VM. Same as 1, except replace Windows with Linux, Linux with Windows, and SSH with RDP. Ever have a powerful server and have a bunch of smaller, less powerful machines you wish you could run on it? Setup a type 1 hypervisor, and kick off some VMs. Ever have a bunch of older servers running various different things (DNS, DHCP, NTP, AD, database, etc) and not enough space in your server rack for everything, consider something like #3, get a powerful machine to run VMs of each of the servers. Ever have a demo kit that you need to send with a non technical person but requires a series of complex server and networking configurations? Set up some VMs they can just start on a laptop they take with them. Virtual machines can be used for many things, development/testing is just one of the big ones I've used them for. Condensing compute power is another, which can at times lead to less energy usage.