This blog post briefly touches on some core concepts of domain-driven design and its built upon the idea of a model and its context.
A model in domain-driven design terms is an abstraction or a group of abstractions of a business model, a set of functionalities and its interactions that need to be implemented and that once completed can be used to solve problems related to such domain.
As models grow in size and complexity (or if they are large in nature) they need to be broken down into more specific models, bounded by the specific context they live in (an easier way to see this is from the end-users point of view), for example a data-entry system that is used by a call center team will give a specific context to the model and its terminology may only make sense to them and not to anyone else outside that context. This is referred to as Bounded Context (BC)
Bounded Context is an important concept in domain-driven design as it provides models with boundaries and their interactions, which in term aids isolating and facilitating its design.