What does "1600mhz compatible with 1333mhz" mean?

Question

macbook

Hello, I want to insert two new RAM sticks, I found Corsair but it has a frequency of 1600 mhz with the caveat that it is compatible with 1333mhz, what does this mean?

Answer 1

Apparently, it means that the bar can lower the frequency itself if the motherboard supports only 1333mhz
Although most (and not all?) memory bars can already do this