What is the difference between the A vs B theory of time and how does it impact our understanding of the nature of time itself?

The A theory of time sees time as having a past, present, and future that are constantly changing, while the B theory sees time as a fixed block with all moments existing simultaneously. The A theory suggests that time is real and dynamic, while the B theory implies that time is an illusion and all moments are equally real. This impacts our understanding of time by shaping how we perceive the nature of reality, causality, and free will.