nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
mod_pagespeed is an open-source Apache module that automatically optimizes web pages and resources on them.
Content Security Policy is best used as defense-in-depth, to reduce the harm caused by content injection attacks.
UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. It is the preferred encoding for web pages.