A mash-up (sometimes spelled as one word, mashup) is a Web page or application that integrates complementary elements from two or more sources.
Mash-ups are often defined by the type of content that they aggregate. A content mash-up, for example, brings together various types of content for presentation through an interface. That content could include -- among other things -- text, data feeds, video and social updates. An enterprise mash-up typically combines internal corporate data and applications with externally sourced data, SaaS (software as a service) and Web content. Business mash-ups might also provide integration with the business computing environment, data governance, business intelligence (BI)/ business analytics (BA), more sophisticated programming tools and more stringent security measures.
Like blogs and social media, mash-ups became popular as part of the ongoing shift towards more a more interactive and participatory Web (Web 2.0) with its greater concentration of user-defined content and services. According to Aaron Boodman, quoted in BusinessWeek online, "The Web was originally designed to be mashed up. The technology is finally growing up and making it possible."
Mash-ups are often created by using a development approach called Ajax, although there are also applications that automate processes. The term mash-up originated in the music industry, where it referred to songs that were combined from two or more other songs.