Error reading CD-R

I got this read error a few times on different CDs:
Data Error(cyclic redundancy check)

then I eject the CD, and try again, and it reads fine.
is it because cd is dirty or media is cheap?

Could be both!

If media is considered of lower grade quality (aka crappy cheap dye) then try it burning at a lower speed. if that still fails try a diff mfg.