The computer blending of two existing files (an example would be a sound track laid over a video it wouldn’t normally go with). With websites, the idea of a mashup is to amalgamate content from other sites in order to create a new one. For example, Google, Yahoo, Amazon, eBay and FedEx have created a mashup enabling them to show on their own websites the status of deliveries they have subcontracted to a logistics company (which they do by joining their site with that of the logistics company). Mashup has taken on a wider meaning over time, that of a derivative application that provides a function not present on a site, an example being Twitturls, which selects the most significant tweets (messages on Twitter). In practice, any site that brings an additional service to another site becomes a mashup.