What technology allows a user to run software for different OS platforms on their computer without multiple physical machines?

The correct choice is the Virtual Machine (VM), which is a software-based emulation of a physical computer that allows users to run multiple operating systems on a single physical machine. Each VM operates independently and has its own virtual hardware, including CPU, memory, and storage. This capability enables users to run software applications designed for different operating systems without the need for multiple physical computers, thus providing flexibility and efficiency.

Virtual Machines are particularly useful in development and testing environments where software needs to be tested across various OS platforms. They allow developers to simulate different scenarios easily without the overhead of managing separate hardware devices. Additionally, they facilitate the consolidation of resources, reducing hardware costs and power consumption, which is a strategic advantage in IT management.

The other options do not serve this purpose. A network switch is used to connect devices within a local network but does not provide virtualization features. A Virtual Private Network (VPN) establishes a secure connection over the Internet but does not virtualize operating systems. Cloud computing generally offers hosted services and resources but does not specifically describe the running of multiple OS on a single machine; rather, it may utilize VMs in its infrastructure but is a broader concept that includes various services provided over the Internet.