What type of data does RAID correct

If I run a level of RAID that has error checking, and a main OS file in one of the harddrives is deleted or corrupted, will that be considered an error and will be corrected by the harddrives? or when they say "error-checking" they mean the checking of data to see if it lost any bits or currupted while being transfered?

thanks

The RAID has no way to know that it is an OS critical file that is missing. Still it will check whether the file has a different number of bits (actually it will check if the parity bit size for that block is different) than the last time it's record was legally modified and if not, it will recreate it accordingly by computing the missing information using the remaining data and the parity information. You can see the simple maths behind this here