Are obito and Tobi the same people?

Tobi and Obito are absolutely not the same person(honestly we have no idea who tobi is, but he is not Madara).It was "revealed" in the episode where Tobi met Sasuke that Tobi is actually Uchiha Madara(but is later revealed he is not as Madara is brought back to life with Edo Tensei.),because he knows the reason why itachi wiped out the entire uchiha clan( which Tobi helped Itachi with),which happened after Obito was dead.The reason why people insist that Tobi and obito are the same person is because of the resemblance it their names.

Possibly,because kakashi's sharingan(left eye) from obito, has power that is whatever he sees it can transfer anything in other dimension/place , and just like Tobi can travel anywhere by dimension by using his sharingan (right eye). They're both using the same sharingan and powers ('cos it come to only one person, obito, and obito himself is Tobi(Possibly)). Kakashi (in manga/anime )can't actually do what Madara/Tobi/obito do 'cos he is not original uchiha(he can access the powers of sharingan but can't deactivate it, which is why he keeps it covered), and only true uchiha can perfect the power of their own sharingan(This is wrong becausethere is plenty of proof towards it but plenty against as kakashi is able to awaken Mangyeko sharingan).