I think it's plainly obvious what the difference between the two is with a simple google search. Bull markets are going up and tend to be longer lasting than bear markets, which are going down. Roughly every three years you have small corrections within a bull market and on average every 8 years there will be a recession. However the age of automation and the internet has changed the dynamics of the economy compared to distant history. Money is constantly moving and adapting to current events, whereas in the past sometimes news would take much longer to spread and reactions via things like brokerages would take longer to complete. Generally people should stick to making money from positive developments and avoid short selling.