Bear – sellers are more than buyers, Bull – buyers are more than sellers.
How can we say that today market is bearish/ bullish on particular stock. If the open price is less than close price then the stock is Bullish. If the open price is higher than the close price then the stock is bearish. So similarly we say market is bearish / bullish based on indecies sensex/ Nifty in india.
TIP: Buy when market is bearish and fearful, sell when the market is over greedy and bullish.