Is Fajr prayer to be recited silently or aloud, and what is to be recited in each rak'ah, and is Fajr the same as Subh, and what should one pray if he wakes up and the muezzin has already called both adhans and he has already prayed two rak'ahs?

There are two prayers after the time of Fajr begins: the Sunnah of Fajr, which consists of two light, emphasized rak'ahs performed before the obligatory prayer. It is sunnah to recite silently in them. The second is the obligatory Fajr prayer (Salat al-Fajr al-Faridah), which consists of two rak'ahs where the worshipper recites aloud. It is sunnah to prolong the recitation in them, and one should be keen to perform them in the mosque with the Muslim congregation.