The probability of an event is a measure of the likelihood that the event will occur. In this case, the event is "randomly selecting a gold coin from the box."
If the probability of selecting a gold coin, denoted as P(gold coin), is 50%, it means that if you were to randomly select an item from the box, there's a 50% chance that the item you select will be a gold coin.
In other words, if you were to repeat the process of randomly selecting an item from the box many times (under the same conditions), about half of the time you would expect to draw a gold coin. This is assuming that after each draw, the item is replaced back into the box, so the conditions remain the same for each draw.
Remember that probability is a theoretical measure, and actual results can vary, especially if the number of draws is small. But as the number of draws increases, the proportion of times you draw a gold coin should get closer and closer to 50%.