Meaning of success rate

Question

What is the meaning of success rate? ex: success rate = 4%

Someone told me it means doing something 100 times consecutively and that there would be at least 4 times it succeeds.

But I think its not true. As far as I understand, 4% success rate of doing something is like when you do it, a perfectly balanced dice with 100 sides is cast, there are 4 green sides and 96 red sides. If you get a green side, you succeed otherwise you fail. So theoretically, you can fail 100 times consecutively or even infinitely because the success rate of a try A exists independently from other tries.

Which definition is correct, 1 or 2 or neither?

If 1 is correct then what do you call 2?

If 2 is correct how do you even calculate the success rate of doing anything? Since there's no way to know how many green/ red sides there are.

The reason Im asking this question is because as a computer science student, I often find myself implementing the success rate in my code using the definition(2). for ex:

randomly take a in (0..9) if ( a <= 3) succeed else fail

Answer 1

Success rate is, first of all, a rate (of success). So naturally its $$ \frac{\#\{\text{succesful events}\}}{\#\{\text{successful events} + \text{unsuccessful events}\}} ~~(= 0.04 = 4\%)$$

here $\#$ denotes a number (count) of events.

Answer 2

If you run the experiment 100 times the 4 times would be the green side ! This is what success rate means.

Yes you can fail 100 consecutively times, but if you run the experiment infinitely you will get an average of 4 percent. You should think of the percentage as a normalized value.