Answer
1. In principle, Sajda-e-Tilaawat is when a person reads certain Aayats of the noble Qur’aan, Sajdah becomes necessary. There are 14 such verses in the Qur’aan.
2. Sajda-e-Sahw is that Sajdah that compensates for any Waajib left out in Salaat, e.g. a person forgets to recite the Qunoot in Witr Salaat, he may cover-up for the missed Qunoot by performing Sajdah-e-Sahw in last Rakaat of the Salat by making one salaam and making 2 Sajdahs thereafter. The Qada Akheerah will be completed as normal.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai