It's the way to bring the language of domain experts into the code. It refers to the use of a consistent, domain-specific vocabulary and language throughout the development process so that there are no conflicting definitions of the same word..

 It is developed and shared by the team, with developers and non-developers alike. A key aspect of a ubiquitous language is that it must be used consistently across all parts of the system, including code, variable and class names, and documentation. For example, in a retail system, a ubiquitous language would use the term 'customer' instead of 'user' or 'customer' to refer to a person who makes purchases.

 In JavaScript, you can use ubiquitous language by creating classes and variables that are specific to your domain, such as:

 In this case, customer can have different definitions from one domain to another, for example, in the domain of a pharmacy it can be anyone who enters, but in the case of a bank, a customer must have a registration. When the same word is used with different meanings it is a sign that we are talking about different domains.