What do line movements tell us?

[Jazzy3113]

I know this is an elementary concept, but when arguing/debating with a co-worker today we both came to different conclusions.

My questions is this. As a line goes through its progession during the week, what exactly does the fluctuation tell you.
I just wanted to see people's opinions. Here are this weeks examples:

1. KC @ Indy: On Tuesday the line was Indy -14.5, it shifted to -15 for two days and now is back to -14.5

2. NWE went from -15.5 to -16 and has stagnated.

3. New Orleans started at +1 on Sunday and moved to +2 where it stayed there from Monday to Thursday. On Friday it moved back to +1.

4. Pitt went from -9 to -9.5

5.Phi went from -10 to -10.5 and back to -10.

6. Tenn keeps shifiting from +2 to +2.5

So what do these movements exactly show? We all know the inputs that go into making lines, but what do I need to take away from the fact that the Saints went from +1 to +2, stayed there for awhile and now are back to +1.
Is it all based on the amount of money that comes in? SImply the books hedging their bets? I am really interested in this particular line and just want to know if it means at first Houston got alot of cash, but then at +2 Cash shifted to NO. Sorry if this is too confusing.