In NCAA mens b.ball, how does the top 25 rankings differ from the complete standings..?

for example teams in the Atlantic Coast division such as Virgina Tech is conf:1-1 All:13-2 and Florida St.is conf:1-2 All: 13-4, THEN WHY IS FLORIDA ST. RANKED 25TH WHEN VIRGINIA TECH IS CLEARLY AHEAD IN THEIR DIVISION???? what does this mean?