usb - dd commands internal working - Ask Ubuntu

how dd command internally works? caches data in copy operation?

i testing usb pen drive read , write speed operation. same block size , same file size show large difference in speed.

dd reads amount of bytes mentioned in bs parameter (default 512 bytes) source on each read(2) call, , writes destination using write(2).

there no caching involved here, buffering involved here data being written.