Salaah

Asalaam
Is duha and ishraq the same orayer?
Which is nafl and which is sunnah

With regard to Duha prayer being Sunnah and mustahabb, it was narrated by al-Bukhaari (1178) and Muslim (721) that Abu Hurayrah (may Allah be pleased with him) said: My beloved (blessings and peace of Allah be upon him) advised me to do three things, which I will not forsake so long as I live: to fast three days of each month, to pray Duha, and not to sleep until I pray Witr.

Regarding witr can we not pray before fajr after tahajud