Re: Help： the difference between via and contact
Contact name is used when it connects the lowest level metal(usually metal1) with poly.
Via term is used when it is used for connecting two metal layers.i.e(via 1 for connecting b/w metal 1 and metal 2,via2 for metal 2 and metal 3 and so on..)
Re: Help： the difference between via and contact
Adding to Chikva's point, a contact is used to connect POLY or P+/N+ DIFFUSION to the lowest level metal.
Vias are interconnects between successive metal layers.