XHR (XMLHttpRequest) is an API that can be used by JavaScript, and other web browser scripting languages to transfer XML and other text data to and from a web server using HTTP, by establishing an independent communication channel between a web page's client and server side. The data returned from XMLHttpRequest calls will often be provided by back-end databases. Besides XML, XMLHttpRequest can be used to fetch data in other formats such as HTML, JSON or plain-text. XMLHttpRequest is an important part of the AJAX web development technique, and it is used by many websites to implement responsive and dynamic web applications. [more]
