Okay kiddo, let me tell you about the women's 4 × 100 metres relay world record progression. Imagine you and your three best friends are running a relay race. Each of you runs 100 meters and passes a baton to the next person until all four of you have run. The fastest time all together is the world record.
Well, there are lots of teams of four women who do this same thing but they run really fast. They compete in races all over the world and try to break the record for the fastest time.
Over time, teams have gotten stronger and faster which means they can run the relay in less time. So, the world record has been broken many times.
The first women's 4 × 100 metres relay world record was set in 1922 and since then, the record has been broken many times. Each time a new record is set, it means that the team is even faster than the one before it.
So, if you were to line up all the teams who have set the world record over time and had them race, the team who set the record most recently would be the fastest of them all.