The purpose of using a virtual machine (VM) in computing is to create isolated environments on a single physical machine. A VM allows multiple operating systems or applications to run simultaneously, mimicking the behavior of separate hardware. This flexibility enables efficient resource usage, testing of software without affecting the host system, and deployment of applications in various environments. VMs can enhance security by isolating different processes and prevent potential threats from compromising the entire system. Consequently, they serve as a crucial tool for developers, IT professionals, and organizations looking to optimize their computing resources.