Cohesion
Cohesion (noun): When the members of a group or society are united.
Cohesive (adjective): United and working together effectively.
Note
Cambridge Dictionary: https://dictionary.cambridge.org/us/dictionary/english/cohesion#dataset-cald4.
Cohesion is a measure of how strongly related and focused the various responsibilities of a software module are, and it "refers to the degree to which the elements of a module belong together."
Cohesion is everywhere, not just in code. For example, companies try to create highly cohesive teams, with cross-functional roles (developers, business analysts, designers, and so forth) that work closely together to achieve a specific goal, such as a software product update.
A component should implement a single behavior or responsibility, and all the parts of the component should contribute to the implementation of it. Components should only be created if all parts they group are collaborating together to implement a behavior...