It's just another transform that gets concatenated with the other transforms. Which one you use depends entirely on what you're trying to achieve.
There's a Position property for the procedural path types like Rectangle, Ellipse and Polygon. Above that there's usually at least one 'Group' Transform as well where the Position, Anchor Point, Rotation, Scale, Skew and Opacity can be adjusted. Whenever you 'Group' paths you'll get another one of these transforms. Then at the highest level there is the standard Layer Transform.
These are applied hierarchically. For example, if you have multiple paths within a single Group and you want them to move independently then you'll need to animate each path's Position property. If there are multiple Groups and you want all of the paths in that single Group to be transformed together then you'd modify that Group's Position property. If you wanted all paths on the layer to be transformed together then you'd modify the Layer Position property.