Define 'data redundancy' in Information Systems.

Data redundancy refers specifically to the unnecessary duplication of data within a database or information system. This means that the same piece of information is stored in multiple places. This can lead to various issues, such as inconsistencies, increased storage costs, and challenges in maintaining data integrity. When data is duplicated without necessity, it not only wastes resources but also complicates data management processes, such as updates and deletions, because changes made in one location may not automatically reflect in others.

In contrast, other options describe different concepts related to data management. For instance, comparing data across systems is a process related to data integrity and accuracy but does not address redundancy. The integration of data from multiple sources focuses on combining separate data sets into a cohesive view, rather than highlighting duplication issues. Lastly, using data to create reports pertains to data utilization and analysis, which does not involve the concept of redundancy directly.