Jackpot is the name given to the top prize in a lottery game. You will usually have to match all of the main numbers drawn to receive a lottery jackpot.
The jackpots, and other large prizes, of some lottery games, are taxed within the state in which they are played, with various governments withholding a percentage of cash prizes above a certain level. Therefore, taxation on lottery winning is highly variable depending on where you are playing the lottery from and your own personal circumstances. It is therefore better for you to check for yourself with a financial expert to get some real advice should you win.