Just off the top of my heads, some benefits of VMs vs processes: - you get the encapsulation/isolation out of the box - abstraction from the hardware; may not seem like a big deal if you're thinking in terms of a single machine but very useful for migration (whether live migration or cold migration) between different machines - ability to snapshot the state - arguably a smaller attack surface since you deal with fewer drivers inside the virtual machine versus a general purpose OS (VM escape exploits do exist though - no denying that).