They are 12 in number.

2 before Fajr, which the Prophet salla Allahu alaihi wa sallam had never left even when he was travelling.

2+2 before Thuhur and 2 after Thuhur.

2 after Maghrib

2 after Isha.

I want to know what is the most authentic opinion about the Sunnah prayers. How many Rakah’s should we perform before and after every fard prayer