What is Cloud ceiling ?

Cloud ceiling - the vertical distance from the aerodrome to the lowest level of cloud visible which is sufficient enough to obscure more than half the sky. It can be more that one type of cloud and the meteorological terminology are a) FEW: 1-2 0KTAS b) SCATTERED (SKC) : 3-4 OKTAS c) BROKEN (BKN) : 5-7 0KTAS d) OVERCAST (OVC): 8 0KTAS