Nginx is a popular web server and reverse proxy server that is known for its high performance, scalability, and reliability. It is widely used by websites, applications, and web services to handle large amounts of traffic and requests. Nginx is also known for its advanced features and flexibility, which allow it to be used in a wide range of scenarios and configurations. Some of the key features of Nginx include load balancing, caching, SSL/TLS termination, content compression, and more. Nginx is also highly customizable and extensible, with a large and active community of developers and users.