Depends on your web server. AFAIK, nginx uses a combination of events and threads to handle a ginormous number of simultaneous connections. See: http://en

Depends on your web server. AFAIK, nginx uses a combination of events and threads to handle a ginormous number of simultaneous connections. See: http://en.wikipedia.org/wiki/Asynchronous_I/O http://www.slideshare.net/joshzhu/nginx-internals http://www.aosabook.org/en/nginx.html http://serverfault.com/questions/86674/why-is-nginx-so-fast Also, Node.js. Edit: formatting.