What tasks are solved with virtual machines and why are they needed?

Virtual machines (VMs) allow running multiple isolated operating systems on a single physical server. This addresses the following tasks:

• Efficient resource utilization: one physical machine can operate as several virtual ones, saving hardware.
• Environment isolation: different applications or services can run in separate VMs without affecting each other.
• Testing and development: quickly create and delete copies of OS with required configurations.
• Security assurance: failures or attacks in one VM do not affect others.

Virtual machines are needed for flexibility, scalability, and ease of infrastructure management in DevOps and IT in general.