more explanation just for fun.
the -f option means follow, and keeps tail open, and keeps doing tail when the file changes. the >> option means to append to a file instead of overwriting it.a single > would overwrite the file each time instead. the & at the end of the line means give me back the prompt and do this in the background. you can bring it back to the foreground with fg and then kill or suspend the process with control-c or control-z. if you control-z, you can run fg and the process will resume in the foreground, or you can run bg and it will resume in the background.