NPHC - National Pan-Hellenic Council - This is the council that governs the historically African-American Sororities and Fraternities. The groups covered under this council can be found here:
http://www.nphchq.org/
NPC - National Panhellenic Conference - This is the council that governs sororities. The sororities covered in this conference can be found here:
www.npcwomen.org
Two completely different organizations.