HI Nazareth, I studied it yesterday in my french lesson. My teacher said to us that french people usually don't distinguish between "deuxième" and "seconde", but the difference exists. She gave us the next example: I live in the "deuxième étage" when I live in the second floor of a building that has more than two floors but I live in the "second étage" when I live in a building that has only two floors and I live in the top one. PS. Sorry for my mistakes in english, I'm spanish! :)

They are interchangeable, but not in every context. The word "deuxième" is used more therefore "safer" for you to use.