Sujud Sahwi or Sajdah of forgetfulness occurs during the ritual salat prayer. Out of forgetfulness a person can either omit obligatory parts of salat (Qabli) or add to the salat (Ba'adi). In either cases the person corrects his/her salat by doing the Sujud Sahwi.
What must I do as remedy for a Magrib that I observed 4 raka'ats instead of three? After Teslim I noticed I did four Raka'ats?