What is better CL15 or CL16?

Question

RAM

I searched on the Internet for information about this, but did not understand. Here, I want to take RAM for myself, there is a choice between
https://ek.ua/KINGSTON-HX426C13PB3K2-16.htm
13-15-15 1.35 V
and
https://ek.ua/CORSAIR-CMW16GX4M2A2666C16.htm
16-18 -18-35 1.2 Q
What is better when the timings are less or more? And what does tension mean? Is more or less better?

Answer 1

The lower the timings, the better.