What defines in-place sorting?

In-place sorting is defined by its ability to sort a list or array while using minimal additional memory beyond the storage required for the original data set. This means that the algorithm rearranges the elements within the same array or list, rather than creating a copy or using a separate data structure that would require additional memory allocation.

When an algorithm is considered in-place, it typically modifies the existing elements directly, often achieving the sorted order through various swap operations among them. This characteristic is important in scenarios where memory usage is a concern or when working with large datasets, as it helps to optimize resource utilization.

While other aspects like overwriting original data may occur in in-place sorting, the key defining feature remains the minimal extra memory usage, which distinguishes it from algorithms that require larger auxiliary storage.