Optionally manages the communications with external programs / internal modules used to generate dynamic content; World wide web servers, serving dynamic content, waiting for slow responses coming from back-end computer(s) (e.g. databases), maybe because of too many queries mixed with too many inserts or updates of DB data; hinein these https://gunnertemrt.blogsuperapp.com/28541019/die-grundprinzipien-der-a-b-tests