Nginx is an open-source web server built with scalability in mind. It uses an event-driven architecture instead of threads to handle the requests, and this means smaller and more predicatable memory usage.
At its earlier stage Nginx proved to be incredibly powerful in serving static contents, but with the increase of global installations and the maturity of the project, it stood out as one of the most widespread and used web servers, with a growing trend.
Nginx is an HTTP/2 server, a reverse proxy, an IMAP/POP3 proxy server, supports static/dynamic content caching and rate limiting, and in fact, one of the production web servers chosen by Kiwee for its projects.