cloud shape ufo witch apears to stay in one place

I have quite a nice view from my front window across the lake, anyway looking over the lake I look up into the sky witch has a few clouds around when one of thease clouds went up into the sky not across but horizontally and then began a slow speed, (drift) down behind a lower cloud going the right way, and stayd at the same speed as the sed cloud this then became a rather big cloud witch seem to be still while others past