Performance modeling is a research area that involves developing mathematical models to predict and analyze the performance of computer systems, networks, and applications. These models help researchers and engineers understand system behavior under different conditions, identify potential bottlenecks, and optimize system resources to improve performance. Performance modeling encompasses a wide range of techniques, including queueing theory, simulation, and statistical analysis, and can be applied to a variety of systems, such as cloud computing, mobile networks, and data centers. By using performance modeling, researchers can make informed decisions about system design, configuration, and resource allocation to achieve optimal performance and efficiency.