The primary purpose of using virtualization in IT infrastructure is to optimize resource utilization and improve operational efficiency. By allowing multiple virtual machines to run on a single physical server, organizations can reduce hardware costs, streamline management, and enhance scalability. Virtualization enables better allocation of resources, isolation of applications, and increased flexibility, as workloads can be moved across different environments easily. This technology is crucial for data centers and cloud computing, allowing for more efficient and cost-effective IT solutions.