How are a members details be checked and verified when they return to log back in to the website ?

When you sign into a website, you have to enter a password and username most of the time, which will allow the website to know that you have checked in and it is you, who is using your account.

answer; availability;

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)