How can data representation be defined?

Data representation can be defined as the way data is stored and organized in a system. This encompasses how information is structured at different levels, whether that's in databases, files, or in-memory structures. Understanding data representation is essential because it affects how efficiently data can be accessed, modified, and processed by software applications. For example, data can be represented in various formats, such as binary, text, or more complex formats like JSON or XML, each of which has its implications for storage and performance.

The other options provide related concepts but do not accurately encapsulate the core definition of data representation. The formal rules for coding pertain more to programming languages and syntax rather than data organization. The methods for visualizing data focus on how data is displayed or interpreted visually, which is a step that comes after representation in a system. Finally, the technique of compressing data files deals specifically with reducing the size of data storage rather than how it is represented in terms of structure and organization. Therefore, the correct definition centers on the organization and structuring of data within systems.