Which option best encapsulates the purpose of Data Modelling?

The purpose of data modelling is fundamentally about the organization and structuring of data to ensure it can be effectively utilized and accessed by various systems. This involves creating abstract representations of how data will be stored, accessed, and manipulated within a database or data structure. By defining the relationships and constraints among different data elements, data modelling paves the way for enhanced interoperability across systems and applications, allowing data to serve its functional purpose across an organization's operations.

While there are elements in other options that touch on important aspects of data modelling, such as understanding data (making sense of it), defining it, and categorizing it, the core emphasis of data modelling is indeed ensuring that data is structured in a way that allows systems to effectively utilize it. This operational efficiency and clarity in data application is what drives effective decision-making and system functionality.