In general terms, online platforms can be seen as intermediaries between supply and demand of goods, services and/or information for actors such as individuals (among which consumers), businesses, science and government. Online platforms are a new phenomenon, which in the last ten years have become increasingly prevalent in different areas of society.
This paper is about the new phenomenon of online platforms: digital intermediaries between suppliers of goods, services and information and (potential) users. The document describes the elements of online platforms, deals with definitions and similar terms, a typology, important political issues and presents some figures on, among others, Airbnb and Uber-like platforms and the perceived effect of online platforms on the turnover of enterprises. It also looks at how and which indicators can best be measured.