and one of them is P-Value / so I know P stands for Probability of 0 to 1 or 0% to 100%

so In general I know that if I am doing an A/B test I am looking for a value of 0.05 p-value to accept an alternative hypothesis, but if there is

just a plot population, what does the p-value mean ? when not compared to anything.

Just trying to clarify that in my brain

Thanks!