Like Bainy said, SP means 'short print'. It is usually used when talking about cards that are NOT numbered, but they produced less of one card compared to another.
Parallel is just an alternate version of a card:
Here is a DeJuan Blair Certified Potential Insert (not numbered)
Here is the 'Parallel' Emerald version which is /5 -
Only a slight difference in the colour of the text/logo!