What is the use of mmap , userptr and dmabuf in video streaming using v4l2 drivers in linux?

enum v4l2_memory {
    V4L2_MEMORY_MMAP             = 1,
    V4L2_MEMORY_USERPTR          = 2,
    V4L2_MEMORY_OVERLAY          = 3,
    V4L2_MEMORY_DMABUF           = 4,

};

Which is one of the fastest and efficient methods for video streaming without any frame drops.