What are the odds?

Odd numbers are any number with 1,3,5,7,9 at the end of them i.e 135

but odds alone is used to represent chances of an event to happen against chances of not to happen, it is in relation to probability but it is not the same. For example, the probability when you throw two dices to obtain 1 and 1 is 1/36 but the odds are represented as 1 against 35, usually represented as 1 : 35.