ECC is an extra error checking function built right into the RAM, but it's typically only used in high end workstations and servers. Only the Mac Pros use ECC RAM, and that's why that particular field is there. It's normal for a MBP, but on a Mac Pro it might indicate a problem.
This site contains user submitted content, comments and opinions and is for informational purposes only.
Apple disclaims any and all liability for the acts, omissions and conduct of any third parties in connection with or related to your use of the site.