These are often used to describe the chances of winning, but are not the same thing.

Probability

Probability allows us to predict how often an outcome or win will occur but does not allow us to predict when exactly it will happen. It is calculated by taking the number of ways an event can occur and dividing it by the total number of possible outcomes. The value of probability ranges from 0 to 1. A probability of 0 means the event will never occur, and a probability of 1 means the event is certain to occur.

For example, when you flip a fair coin, the probability of getting heads is 1/2, or 0.5. There's one favourable outcome (getting heads) and two possible outcomes (getting heads or tails).

Odds

Odds is a term used to describe the chances a person has of winning. Or to put it another way, odds are how many chances there are to lose for every chance there is to win.

For example, if 100 people enter a draw, there are 99 chances the winning ticket won’t be theirs (they lose) and one chance that it will be theirs (they win). So, the odds are 99 to 1 (99 chances to lose and 1 chance to win).

Odds means something different for table games and slot machines, it refers to the total amount you are paid if your bet wins. If the odds are 2 to 1 it means that for each $1 wager any winning outcome will pay a total of $2.

Often in gambling, the more chances there are to lose, the bigger the potential win. Where the odds are 99 to 1, your chance of winning is small, but if you do the payout is high. Where the odds are 2 to 1 your chance of winning is higher, but your payout is lower.

Lottery

For the lottery, odds and probability mean the same thing. They both refer to the mathematical likelihood of winning. For example, the odds of winning a 6/49 jackpot are 1 in 13,983,816. Expressed as a probability, you have a 0.00000715112384 percent chance of winning. In other words, it’s very unlikely.