So on snap u can see where/ how people got ur username and added u. where did they add u from when it says mutuals?

It says mutuals because they have the same friends as you.

the answer to your question would be something called hertz. the unit of measurement called a hertz, which is one cycle per second, is used to measure clock speed. within one cycle, your computer processes, refreshes, or updates itself to the changes that it is going through. in the case of computer clock speed, one hertz equals one tick per second. the clock speed of computers is usually measured in megahertz (mhz) or gigahertz (ghz)