Nginx, pronounced like “engine-ex”, is an open-source web server that, since its initial success as a web server, is now also used as a reverse proxy, HTTP cache, and load balancer.
Nginx is built to offer low memory usage and high concurrency. Rather than creating new processes for each web request, Nginx uses an asynchronous, event-driven approach where requests are handled in a single thread.
With Nginx, one master process can control multiple worker processes. The master maintains the worker processes, while the workers do the actual processing. Because Nginx is asynchronous, each request can be executed by the worker concurrently without blocking other requests.