Hijab is an Arabic word and means: veil.And it gives the idea of a woman being placed behind a curtain, and Islam has wanted women to always remain behind a curtain, to be imprisoned in the house! But Islamic covering does not necessarily mean that they should not leave their homes. Because the philosophy behind the hijab for women in Islam is that men (strange person = Na Mahram) look at her as a human. And she does not flaunt and display herself. So we choose the word of Efaf which mean modesty. And it is in dressing, talking, walking and … . And it is also for women and men.
Source (with changes): Mutahhari, Murtedha, Islamic Hijab Modest Dress; translated by Bakhteiar.