SQL Server Management Studio – adding foreign key confusing?

Question

Click the expand symbol next to the table.
Right click on the “Keys” folder and select “New Foreign Key.”
(Alternatively, you can click the Relationships button on the toolstrip when you have the table open)
Click the “…” button on the “Tables and Columns Specifications” row to open the editor.
The drop down on the left will be the table you’re adding from, and the static text field will list the table you’re adding to.
Use the dropdowns to specify your constraints, and be sure both sides have the same number of columns.