Whereas a bear market is a financial market in which prices are in a prolonged period of decline, a bull market means that, in general terms, prices are rising. More specifically, its reserved for a market in which security prices are rising for an extended period. Bull markets can last for months or years and tend to last longer than bear markets.
Example: The last bull market ended in 2019 and was one of the longest bull markets in history. It lasted from about 2009 to 2019, meaning that it was a 10-year bull market (the second-longest bull market started in October of 1990).