Looking at the BIP32 definition, I hit a line that I would appreciate
clarification on.

https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki

Under the section "Private parent key → private child key" there is a step:

"The returned child key ki is parse256(IL) + kpar (mod n)."

Can someone help me understand what "n" is in the context of this
algorithm?  I very well could be looking right at it, but wanted to double
check if I am missing something.

Thanks,
James