Probability in math is a chance of something to happen.
It can be expressed between 0 which means that I can never happen to 1 which will always happen.
For example: if you flip a coin for it to turn on “tails”
The probability of that to happen is 1/2 since there are two sides
Another example is: the sun to rise
The probability is 1 since it is certain to happen.
Lastly, another example is:
A human being able to fly by using their arms.
The probability of this is 0 since it cannot happen.
Hope this helps! :3