A pingback is one of four types of linkback methods for Web authors to request notification when somebody links to one of their documents. This enables authors to keep track of who is linking to, or referring to their articles.
nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.
LiteSpeed web server is a light-weight server which conserves resources without sacrificing performance, security, compatibility, or convenience. It is capable of handling multiple concurrent clients with minimal memory consumption and CPU usage.
Open graph description entity tag