What are blocks in OutSystems?

In OutSystems, blocks are defined as reusable screen components that can hold a variety of widgets and patterns. This functionality allows developers to create encapsulated pieces of user interface elements that can be utilized across different screens or modules within an application, promoting consistency and reducing redundancy in design.

Using blocks enhances efficiency in development, as once a block is created, it can be easily reused wherever needed, allowing for a modular approach to building applications. Additionally, it simplifies maintenance; if a change is required, it needs to be done only once in the block rather than in multiple places throughout the application.

The other options do not accurately describe what blocks are in the OutSystems environment. For instance, server-side data storage units refer to database entities or data models, which are fundamentally different from the concept of reusable UI components. Predefined user settings would pertain more to application configuration or preferences, while OutSystems-specific libraries would generally refer to code libraries that provide functionalities but do not align with the definition of blocks. This clarity in function is central to understanding how to effectively utilize blocks in OutSystems development.