Online dating or Internet dating is a personal introductory system where individuals can find and contact each other over the Internet to arrange a date, usually with the objective of developing a personal, romantic, or sexual relationship.

Online dating sites use market metaphors to match people.

Match metaphors are conceptual frameworks that allow individuals to make sense of new concepts by drawing upon familiar experiences and frame-works.

This metaphor of the marketplace – a place where people go to "shop" for potential romantic partners and to "sell" themselves in hopes of creating a successful romantic relationship – is highlighted by the layout and functionality of online dating websites.

The marketplace metaphor may also resonate with participants' conceptual orientation towards the process of finding a romantic partner.

Most sites allow members to upload photos or videos of themselves and browse the photos and videos of others.

Sites may offer additional services, such as webcasts, online chat, telephone chat (VOIP), and message boards.Some sites provide free registration, but may offer services which require a monthly fee.Other sites depend on advertising for their revenue.Some sites such as Ok Cupid.com, and are free and offer additional paid services in a freemium revenue model.Some sites are broad-based, with members coming from a variety of backgrounds looking for different types of relationships.Other sites are more specific, based on the type of members, interests, location, or relationship desired.