Two-Sided Market is defined in theory as a market in which a supplier provides its products or services to different types of end-users while enabling interactions between end-users, and tries to charge each side. Examples for these kinds of markets include media, as they sell their services to advertisers and viewers, or payment card systems providing services both to merchants and cardholders.
Additional meaning of Two-Sided Market:
The term is also used for securities meaning that a bid price and an ask price are both quoted for a security. In this case market makers must buy and sell securities at the prices they quote.