mmap (system call)

The `mmap` system call is a way for programs to directly access files or memory regions by mapping them into their address space. Instead of reading a file into buffers, `mmap` links a portion of the file to a specific area in the program's memory, allowing for efficient data access and manipulation. This technique is useful for handling large files, enabling faster I/O and shared memory between processes. Essentially, `mmap` creates a direct connection between disk data and program memory, simplifying data handling and improving performance.