Drupal 8 works on any web server with a PHP (7.1 Recommended). PHP memory requirements can vary significantly depending on the modules in use on your site. Minimum required memory size is 64MB (Usually 128 MB - 256 MB)
Apache is the most commonly used web server for Drupal. Drupal will work on Apache 2.x hosted on UNIX/Linux, OS X, or Windows.
Nginx is a commonly used web server that focuses on high concurrency, performance and low memory usage.