To use NGINX for virtual hosts (preferably name based) you can use the following technique. Your main NGINX config file includes all the site which are enabled for NGINX, following the sites-available / sites-enabled approach found e.g. with Apache.
To achieve this, first you need to configure your NGINX for inclusion of the servers and enabling the proxy modules in you nginx.conf
proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_buffers 4 32k;