We sing the blessing over the candles as we enter Shabbat and Jewish holidays. On Jewish holidays the ending of the blessing will be different. By lighting the candles we are welcoming in Shabbat. The candles are lit prior to saying the blessings, and you will notice people covering their eyes after lighting during the recitation of this prayer. As we are not allowed to kindle fire on Shabbat, it is a moment where we technically bless after performing the task. Traditionally one blesses prior to the task. Thus, when we uncover our eyes it is almost like a miracle that the candles are now lit. Reciting the blessing over the candles is often an honor given out to members of the congregation.