Lines moving?

[BabyMatrix27]

Can someone please explain to me what does it mean when a Line moves? Who does it favor, etc
For Ex, Saints @ Raiders opened up at -5.5 and now one day later it went to -4.5

[Roscoe_Word]

Line moves could occur because of injuries, weather, one sided action, or a big bet from a sharp.

In your example, "who does it favor" depends on who you like.

If you liked the Saints, the move favored you.

If you liked the Raiders, it didn't.