Creating a radio button with 2 values only ?

Dear 

i want to create a radio button with 2 values only, what is the best way to go at it , 

1. Create a table with those 2 values and link it to the field on the form
2. I don't know what option 2 is ? is there a way to load the values directly on the field itself, without having to create a table for it 

regards