Final answer:
Data redundancy is the unnecessary repetition of data in a database, which can lead to errors and inefficiencies. Flat-file problems occur when data is stored in a single file without any structured format or relationships, making data retrieval and manipulation difficult.
Step-by-step explanation:
Data redundancy occurs when the same data is unnecessarily stored multiple times in a database, leading to wasted storage space and potential inconsistencies when the data is updated. This can result in errors and inefficiencies in data management.
Flat-file problems refer to the limitations of using a single flat file to store data. A flat file is a simple, text-based file that does not have a structured format or a way to establish relationships between data. This can make it difficult to retrieve and manipulate data efficiently.