What are the Sunnah prayers, the accompanying (tawabi') prayers, and the voluntary (nawafil) prayers, and what is the difference between them?

Voluntary prayers (Nawafil) are all prayers other than the obligatory ones (Fara'id). They are divided into two categories: those that are dependent on the obligatory prayers (Al-Rawatib or Sunan Al-Fara'id), and those that are not Al-Rawatib. Al-Rawatib are of two types: confirmed (Mu'akkadat) - twelve rak'ahs: four before Dhuhr, two after Dhuhr, two after Maghrib, two after Isha, and two before Fajr; and unconfirmed (Ghair Mu'akkadat) - four before Asr, two before Maghrib, and two before Isha. As for voluntary prayers that are not Al-Rawatib, they are numerous, including Witr and Duha. Some of them are considered confirmed Sunnahs, such as the Eid prayers, Istisqa' (prayer for rain), and Kusoof (eclipse prayer). There are also absolute voluntary prayers that are not restricted by number, and can be performed at any time except during the prohibited times.