What type of processing involves handling large amounts of data all at once when the system is not busy?

Batch processing is a method used to handle large volumes of data by collecting and processing it in groups or "batches." This approach is particularly effective when the system is not engaged with other tasks, allowing for efficient resource utilization.

In batch processing, data can be processed at scheduled intervals rather than in real-time or as it arrives. This makes it ideal for tasks like payroll, billing, or data analysis, where immediate processing is not necessary and you can work with a large set of data at once. It contrasts with real-time processing, which focuses on immediate data handling, and transaction processing, which manages individual transactions as they occur. Stream processing deals with continuous flow data but does not group it like batch processing does.

Overall, batch processing is suitable for situations where efficiency can be maximized by waiting until a significant amount of data is collected before processing, allowing systems to perform other tasks during idle times.