Night prayer (Salat al-Layl or Namaz e Shab) is the most recommended Mustahab prayer every night. It is very easy to remember as it has four units of two Rak'ats each just like morning prayers, then another two Rak'ats called Shaf'a شفع then just single Rak'at called Witr. These 11 Rak'ats are the full form of Night Prayer. There is shorter form of it which contains just the two Rak'ats of Shaf'a and the single Rak'at of Witr. The shortest form is just the single Rak'at of Witr alone.