Ubiquitous Language is the language of the business. It is the terminology that has subtle and specific meaning to the team. Ubiquitous language must permeate the team's lexicon. It drives the names of interfaces, methods, and interactions within the application. Code comments will reference the language. Water-cooler chats will bandy the terms back and forth. ==The team's ubiquitous language is the heart of the model upon which a fundamental shared understanding of the domain is rooted.== Terms in one team's ubiquitous language may overlap with other teams, but each team may have different interpretations of what that word means in practice and that's OK—so long as each team remains true to their own meaning of the word.