Word of mouth is the passing of information from person to person using oral communication, which could be as simple as telling someone the time of day. Storytelling is a common form of word-of-mouth communication where one person tells others a story about a real event or something made up.

Word of mouth is the passing of information from a person to one or more people in conversation. In the past, it referred only to speech, but now, it can sometimes include online communication. It can be as simple as telling someone what time it is, or it can involve longer stories and news.

Word-of-mouth marketing (WOMM, WOM marketing, also called word-of-mouth advertising) is the communication between consumers about a product, service, or company in which the sources are considered independent of direct commercial influence that has been actively influenced or encouraged as a marketing effort (e.g. 'seeding' a message in a networks rewarding regular consumers to engage in WOM, employing WOM 'agents').