A fake computer that runs inside a real computer. It's like having multiple phones running on one device.
You can run Windows and Mac operating systems at the same time on one computer using virtual machines.
All four services provide virtual machines (guest OS instances) running on provider-managed physical servers. They differ mainly in instance types, pricing models, networking/storage integrations, and management features, but the core concept—provisioning CPU/RAM/disk for an OS you control—is the same.
Explore real-world architectures from our community that use Virtual Machine: