A virtual machine (VM) is a software-based simulation of a physical computer, allowing multiple operating systems to run on a single hardware platform. VMs are used for various purposes, including software testing, running applications in isolated environments, and optimizing resource utilization. By mimicking physical hardware, VMs provide flexibility and scalability, enabling organizations to deploy and manage applications efficiently. Virtual machines are crucial in cloud computing, as they allow users to leverage powerful computing resources without needing physical infrastructure.