poser versus déposer

[alan gould]

I learned the latter to mean "to drop someone off" (at the train station, etc. after giving them a lift).  But I now see that "poser" can be used as well.  Is there a distinction?  Is one used more than the other, more "proper" than the other?  

I also see the two being used to mean "to put something down" and both referred to something heavy such as a suitcase.  I was inclined to think "poser" is used for something lighter that would be put on a table.  Please distinguish.  

merci d'avance