Load balancing is the fundamental technique for distributing network traffic across multiple servers to ensure no single server becomes overwhelmed, improving application availability, scalability, and fault tolerance. Operating at various layers of the OSI model—from network to application—load balancers act as intelligent traffic directors that continuously monitor backend server health and route requests using sophisticated algorithms. What makes load balancing essential is that it transforms individual servers into resilient, horizontally scalable systems capable of handling millions of requests per second while maintaining sub-second response times and near-perfect uptime.