Tell Me The Odds: A 15 Page Introduction To Bayes Theorem

the way we account for whatever initial probability estimates we have is by multiplying the prior probability by each individual likelihood.

Bayes Theorem is the same type of probability you already know, just in reverse.

The reason we bother with Bayes Theorem is that we live in a world where we frequently see outcomes but have to guess at the initial events that caused those outcomes.

The prior is how you account for your initial estimate of probability before incorporating new data.