Which of the following is a method to save space in data storage?

The method to save space in data storage is data reduction. This technique involves minimizing the amount of data that needs to be stored, which can be achieved through various strategies such as compression, deduplication, and aggregation. Compression reduces the size of files by encoding data more efficiently, while deduplication eliminates duplicate copies of data, and aggregation combines multiple data elements into a single representation. By effectively reducing the volume of data that must be stored, organizations can save on storage costs, improve efficiency, and optimize performance.

In contrast, data entry refers to the process of inputting data into a system, which does not address storage efficiency. Data analysis involves examining and interpreting data to extract insights but also does not focus on reducing the storage footprint. Data retrieval is the act of accessing and retrieving data from storage, which is inherently unrelated to the management of storage space itself.