Independent and interdependent.
As the baby's head moves down it moves in stations. The higher it is in your pelvis the lower the number from -4 to 0, then as it moves down into your pelvis the numbers go higher.
Effacement is how thick your cervix is, so think of it vertically. How long the cervix is at the time. If you are not effaced at all its at its full length but as the head creates pressure it starts to get shorter.
Dilation is how open it is and is related to effacement, they usually happen together. The head presses down and shortens the cervix while at the same time the cervix opens up. 10cm isn't an exact measurement by the way. 10cm means your cervix is all the way open but that is not exactly 10cm for each woman.one picture to explain itanother onethis one shows effacement best, I think
The cervix also makes a few other moves. During pregnancy its usually posterior (near your butt) but as labor progresses it moves forward to the anterior. I think this is one of the last things that usually happens.
I hope that helps and isn't too confusing.