The term Nafilah or Nawafil refers to all mustahabb prayers; in other words, mustahabb prayers, which are all prayers other than the obligatory daily prayers (seventeen rak’ahs), are all nafilahs. Many different mustahabb prayers or nafilahs have been taught and pointed to in our hadiths; we will explain the daily nafilahs that have been emphasized on more. These nafilahs are 34 rak’ahs in days other than Friday (on Fridays, this number somewhat doubles): the morning nafilah (2 rak’ahs), the dhuhr nafilahs (8 rak’ahs), the asr nafilahs (8 rak’ahs), the maghrib nafilahs (4 rak’ahs) the isha nafilah (2 rak’ahs)  and the night nafilahs consisting of 8 rak’ahs of night prayer, 2 rak’ahs of the shaf’ prayer and 1 rak’ah of the watr prayer. 
For further information on how to perform these nafilahs, refer to:
1- How to perform mustahabb prayers, Question 3109 (website: 3377).