The Wajibat (essential or necessary parts) is the second category. These are the parts which, if left out wilfully, will invalidate the Prayer, but if forgotten and remembered afterwards, may be condoned by offering two Prostrations of condonement towards the end of the Prayer. The Prostrations of condonement are deemed sufficient to rectify the mistake and the missed function is not repeated in this case. The Wajibat of the Prayer are as follows:
The recitation of a portion of the Holy Quran after reciting Surah Al-Fatihah in the first two Rak‘at of the Fard part of the Prayer and in all Sunnat and Nawafil Prayers.
Standing erect after Ruku‘, technically called Qaumah. Note: Qiyam is a Fard part, i.e. is compulsory, while Qaumah is Wajib i.e. essential or necessary.
Jilsah, the sitting position between two prostrations.
Short sitting position after completing the first two Rak‘at (not the final Qa‘dah).
Recite Tashahhud, i.e. At-tahiyyatu Lillahi was-Salawatu... in Qa‘dah position.
For the Imam to recite Surah Al-Fatihah and a portion of the Holy Quran audibly in the first two Rak‘at of Fajr, Maghrib, ‘Isha’, Jumu‘ah and ‘Id Prayers, and to recite the same silently in Zuhr and ‘Asr Prayers.
Tartib, i.e. to perform various Fard and Wajib parts of the Salat in their appropriate order.
Ta‘dil i.e. to perform all parts of the Prayer with dignity and respect. In other words the Salat (Prayer) should be offered with full concentration and without any haste.
To turn the face to the right and to the left, saying Assalamu ‘Alaikum wa Rahmatullah, to mark the end of the Prayer.
For the Imam to say Takbir-i-Tahrimah aloud.