Nginx is a free, open-source, lightweight, and high-performance web server around the world. It is specially designed to address the performance limitations of Apache web servers. It uses an event-driven architecture and can handle multiple requests within one thread. Generally, Nginx is often used as a reverse proxy or caching service. Nginx reverse proxy is a proxy service that directs client requests to one or more backend servers. You can use Nginx reverse proxy for various protocols such as HTTP, HTTPS, TCP, UDP, SMTP, IMAP, and POP3.