What is the difference and use of seams and pins in UV Unfold. I have been using seams but I don't understand how to use the pins.

I have a feeling this is why my textures from UV Unfold are coming into Carrara all messed up.

Seams 'seem' easy enough but to do, but how does one use the pins? I have a feeling pins hold the texture in place on the object. Can someone verify this and how to use the pins in UV Unfold?

Also, does one UV Unfold before or after displacement? Will displacement screw up UVs? I know for texture painting you need to UV map your object and create a texture map in the materials before you can paint. I know I am doing something wrong from the results showing up in Carrara.

Anyone out there with some insight on this?

Appreciated