Domain – A realm of influence, knowledge, or activity. The topic or area that the technical expert in the project uses to create the design.

Model – A series of abstractions that wholly but briefly describe the essential aspects of a domain and that can be used to perform operations and solve problems in that domain.

Bounded context – A description of boundaries (typically a subsystem within the domain) within which the model is defined and applied. There is a high correlation between project size and project complexity. With the project size, more models will likely be required to describe the domain. When the project size increases, the code bases become more prominent, and more models must be created. In that case, there is a higher interaction between models, which could translate into more bugs, less reliability, less understanding of the code, and more confusion among team members. In short, more complex. Therefore, with more significant projects, we need to be more aware of defining the context within which a model applies. We must explicitly set boundaries regarding team structure and how specific components are used.