As SystemDown said, these salats are called الرواتب Arrawatib.
Aishah narrated that Allah's Messenger (S) said: "Whoever is regular
with twelve Rak'ah of Sunnah (prayer), Allah will build a house form
him in Paradise: Four Rak'ah before Zuhr, two Rak'ah after it, two
Rak'ah after Maghrib, two Rak'ah after Isha, and two Rak'ah before
Fajr." (Hasan)
Atirmidhi
Two Rakat's before fajr and four before Dhur
It was narrated from Aishah that: The Prophet () would not omit four
rak'ahs before Zuhr and two rak'ahs before Fajr. (Sahih)
أَخْبَرَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، قَالَ حَدَّثَنَا عُثْمَانُ
بْنُ عُمَرَ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ إِبْرَاهِيمَ بْنِ
مُحَمَّدٍ، عَنْ أَبِيهِ، عَنْ مَسْرُوقٍ، عَنْ عَائِشَةَ، أَنَّ
النَّبِيَّ صلى الله عليه وسلم كَانَ لاَ يَدَعُ أَرْبَعَ رَكَعَاتٍ
قَبْلَ الظُّهْرِ وَرَكْعَتَيْنِ قَبْلَ الْفَجْرِ . خَالَفَهُ
عَامَّةُ أَصْحَابِ شُعْبَةَ مِمَّنْ رَوَى هَذَا الْحَدِيثَ فَلَمْ
يَذْكُرُوا مَسْرُوقًا .
Four before Dhur and two after
Ali narrated: "The Prophet (S) would pray four Rak'ah before Az-Zuhr
and two Rak'ah after it." (Hasan)
in some hadiths it is four after,
The Prophet () said: "Whoever prays four rak'ahs before Zuhr and four
after, the Fire will not touch him." (Sahih)
Four before asr
The Prophet {Peace be Upon Him} said that may Allah's mercy be on one who makes four before Asr. Atirmidhi
Two Rakas after Maghrib
Two Rakas after Isha'
3 witr
actually, if one wants one can make a seven Raka witr, five, three, or one. Annasa'i the Prophet {Peace be Upon Him} used to make thirteen Rakahs witr, atleast until He got older/weaker he than preformed seven. Atirmidhi The Prophet also used to finish witr when it was the time Dawn. Muslim