A:Answer Dave,
RAM is memory when you turn on the computer, when you turn off the computer, it clears out. It doesn't store info so don't worry if you'll "lose everything stored in Ram." The 500GB hard disk does that job. So, when you purchase a second 4GB RAM stick, turn off your computer, plug it in, turn it back on, your RAM memory will show that it increased to 8GB. RAM stands for Random Access Memory. Hope this help.