What describes a monolithic application?

A monolithic application is best described as a single program where the user interface (UI), business logic, and data access components are tightly integrated into a single codebase. This architecture means that all the different functionalities of the application are interconnected and often run as a single service.

When a monolithic application is modified, whether for adding new features or fixing bugs, the entire application must be redeployed, which can lead to challenges in scaling and maintaining the application. This characteristic highlights a key trait of monoliths: they lack the flexibility and modularity found in other architectural styles, such as microservices, where components can be updated independently.

The other options describe architectural styles or behaviors that do not align with the definition of a monolithic application. For instance, multi-tiered architectures typically involve separating concerns into different layers, which contrasts with the unified structure of a monolith. Similarly, scaling automatically with demand or being classified as outdated does not pertain to the fundamental definition of what constitutes a monolithic application itself.