How does memory-mapped files impact performance or memory usage?

Memory-mapped files provide a mechanism for efficiently reading and writing files by mapping them into the memory address space of a process. This approach can significantly boost performance when dealing with large files or when multiple processes need to access the same data concurrently.

Key benefits include reduced I/O operations, as the operating system handles paging in and out of memory, and the ability for multiple processes to share the same memory space without needing to copy data. However, it's essential to manage memory efficiently to avoid excessive usage and ensure that the application performs optimally.