Whether... Or
This correlative conjunction is used to introduce alternative conditions, possibilities, or choices. It indicates that the outcome will be the same no matter which option occurs.
Expressing Alternatives
I am going to buy the car, whether it is expensive or cheap. Whether you like it or not, we are leaving.
Indirect Yes/No Questions
"Whether" is often used instead of "if" in formal indirect questions where there is a choice (even an implied one).
I don't know whether he will come (or not). She asked whether I wanted tea or coffee.
Prepositions
You MUST use "whether" (not "if") immediately after a preposition.
We are talking about whether to move. (NOT: about if to move).