NVIDIA's SLI (Scalable Link Interface) is a technology that allows multiple NVIDIA graphics cards to work together in a single computer system. This setup enhances graphics performance by distributing the workload across the cards, resulting in smoother gameplay and improved frame rates in demanding applications. SLI is particularly beneficial for gamers and professionals who require high-quality graphics rendering. By connecting two or more compatible NVIDIA GPUs, users can achieve better performance in video games and 3D rendering tasks, making it a popular choice for high-end gaming rigs and workstations.