HAProxy is an open-source software that acts as a load balancer and proxy server for TCP and HTTP applications. It helps distribute incoming network traffic across multiple servers, ensuring that no single server becomes overwhelmed. This improves the performance and reliability of web applications by providing high availability and fault tolerance. In addition to load balancing, HAProxy offers features like SSL termination, health checks, and session persistence. It is widely used in various industries to enhance the scalability and efficiency of web services, making it a popular choice for managing large volumes of traffic in real-time.