If the errors only occur on my CD or DVD then that CD/DVD is probably dirty or scratched. Look at the back and if you see smudges get a clean wet (plain water) soft cotton cloth and wipe from the center to the outside. Usually smudges will come off and after it dries it works. If it is scratches you can do the same thing as sometimes what looks like a scratch is dirt. If it is scratches there are scratch repair kits you can buy (where ever computer supplies are sold in computer and discount stores, etc) and try. I know some people these work well for and others they did not.
If you are having the errors appear on a number of CDs and DVDS then it is likely the lens in the CD/DVD drive is dirty. The drive is sending a laser thru the lens hitting the CD/DVD and bouncing back. The lens will pick up dust and dirt over time and become hard for it to read or write. Keeping your CD/DVDs clean by keeping in covers and keeping your CD/DVD drive closed (if it is a tray type drive) will keep the dirt down, but there is dist in the air and some places are dustier than others.
You can buy a CD/DVD drive cleaner for about $10 at computer supply locations. It is a CD with a number of small brushes on it. Basically you will put the cleaner CD in the drive and the drive will turn trying to read the CD and the brushes will wipe the dust off. Some of the cleaner kits include software that tells you exactly how your drive is doing and some extra tools to tune your drive. Cleaning the drive is not more complicated than playing a CD or DVD.
It is not recommended by most experts to clean a CD/DVD drive until it begins acting up as you are hitting the laser lens head with a brush and the brush can gradually either scratch the lens or knock it out of alignment.