If you’ve ever tried to install PHP on a Debian box, you may notice that is also tries to bring in Apache as well.
This is great if you actually wanted to use Apache, but if you wanted to use another webserver (nginx, lighttpd, etc) this is a bit of an issue.
You can however get around this by doing:
sudo apt-get install php5-fpm php5-cli php5
Under Debian/APT PHP has a hard dependency on either of the FPM or CGI versions of mod_php. As such, when attempting an install it will try and find the first available version and install this one. This typically means you get Apache as well. With this you can setup, install and configure PHP with your preferred choice of webserver