What is Nginx ?
Nginx is an HTTP server and a free reverse source-based reverse proxy, which can also be used as an IMAP / POP3 proxy server. This software was created by Igor Sysoev in 2002, and was released for the first time in general in 2004. Currently Nginx is used by 7.65% (22.8 million) domain names worldwide.
Nginx is famous for its high performance, stability, has many features, is easy to configure, and uses only a few resources on the server.
Nginx is one of a small number of software for servers created to solve the C10K problem. Unlike other common server software, Nginx does not rely on threads to service clients. In contrast, Nginx uses a more stable asynchronous architecture. This architecture requires less memory, and more importantly, can be estimated.
Even if you don't expect your server to handle thousands of connections at the same time, you can still benefit from a small but high-capacity memory usage. Nginx can be used on all scales: from small VPS to large cluster servers.
Nginx is used by several well-known websites such as: WordPress, Hulu, Github, Ohloh and TorrentReactor.
More information about Nginx : https://www.nginx.com/resources/wiki/