CPC is the College Panhellenic Council.  You may also hear it called "Panhel" or "Panhellenic".  It is the collection of women's sororities who partipate in "formal recruitment." 

All of these groups are members of the National Panhellenic Conference.

IFC is the Interfraternity Council. It is the collection of men's fraternities who partipate in "rush." 

All of these groups are members of either the North American Interfraternity Conference, or Fraternal Leadership Association.

NPHC is the National Pan-Hellenic Council.  It is the collection of historically African-American fraternities & sororities who partipate in "membership intake." 

Collectively, these groups are governed by the NPHC, Inc., and are referred to as "the Divine 9".