The Geek Stuff compared Nginx and Apache
The need for serving large number of concurrent requests is raising every day. The prediction of C10K problem (i.e 10,000 concurrent clients) started the research on web server architecture which could solve this problem. As a result Nginx architecture was developed.Nginx Vs Apache: Nginx Basic Architecture and Scalability
This article explains on a very high-level how Nginx works to solve the scalability problem, along with high level differences between Nginx and Apache webserver.