What types of virtual machines have you used in your practice?

In QA practice and test automation, the following types of virtual machines are often used:

• Full virtual machines (VMs): for example, VirtualBox, VMware. They emulate a complete hardware stack, allowing you to run different operating systems and test applications in an isolated environment.
• Lightweight virtual machines (containers): Docker, Podman. They use the host OS kernel and provide process-level isolation, which is faster and more efficient for testing applications.
• Cloud virtual machines: AWS EC2, Azure VM, Google Compute Engine. They allow quick creation and scaling of test environments.

The choice depends on the testing goals: full VMs are often used for integration and system testing, while containers are preferred for testing microservices and CI/CD.