The biggest difference is that nginx uses an evented I/O, and handles many connections per thread/process, Apache can only handle one at a time. This allows it to to use far less memory per connection, and lets it perform reasonably under very high loads. It also has very low latency, even for small loads, and is relatively easy to install and configure on most platforms.
nginx does an excellent job as a reverse proxy for applications, there are many configurations where nginx acts as a load balancer, and serves static content, and everything else is passed off to a real application. It's also useful if you're running on a tiny VPS with very little RAM.
However, Apache has a few features that nginx lacks, like embedding languages into it like mod_php does, and per directory configuration, in that directory.
>I have not used nginx, and have never heard of it spoken about in such glowing terms.
Seriously? There are lots of glowing blog posts, articles etc about Nginx all the time, including on HN. Just last week or so, it was reported that it powers the majority of the top-1000 biggest sites.
Yeah I guess what I mean was the post I was replying to called it the most useful tool powering the internet. I have not seen that before. I also like to ask people on HN who seem extremely passionate about something to explain why they are passionate because you often learn something new, that you often would not from articles etc.
