XMLHttpRequest

Abbreviated as XHR, XMLHttpRequest is a set of APIs that can be used by Web browser scripting languages, such as JavaScript to transfer XML and other text data to and from a Web server using HTTP. XMLHttpRequest works by establishing a communication channel between a Web page’s client-side and server-side. XMLHttpRequest can be used to fetch data in a number of formats including XML, HTML, JSON or plain text. Examples of applications using XMLHttpRequest include Google Gmail and Google Maps. Browsers that support XMLHttpRequest include newer versions of Internet Explorer, Mozilla and Safari.