That's the same thing. When you want to import goods, you provide information to the customs officials at the location those goods enter the country saying:

* Here's what I'm importing

* Here's where I'm importing it from

* Here's the value

Then you pay a bill based on that value and the tariff, and they let your goods clear customs and get loaded onto a truck to go wherever you want them to go in the US.

If you're shipping something by boat (like most goods), the "point of import" is the port.

Note: this is all actually much more complicated and individualized than I described because of networks of middlemen, logistics companies, distributors, manufacturers and lawyers.