Hijab means covering. Before describing the hijab, it is better to explain the two terms Mahram and Unmahram. In Islam husband and wife together are Mahram.
These are called causative Mahram. That is, they are Mahram through marriage. Brothers and sisters are Mahrams. Children are Mahram with their parents and grandparents. Aunt, uncle, auntie, and aunt are Mahram. This second category is called relative Mahram. Relatives are okay if they see each other’s hair, or touch each other’s body (except their genitals). But they are not allowed to marry together . Islam believes that not only non-religious sexual intercourse is forbidden, but also that it is forbidden to look at a man for the pleasure of the female body, and vice versa.
In Shiite religion, a woman must protect her body like a precious gem. And he is only allowed to give it to his wife.
Therefore, in Islam women are permitted only to have their face and wrist exposed. Apart from wearing the body, the clothing should not be too tightly clipped, which may indicate the prominence of the female body.
The man’s clothing should also be such that it is not visible to the ladies from the navel to the knee. Also, it is forbidden to look at the man in the same way as he pleases. It is forbidden to see a man’s genitals by another man, even without the intention of pleasure.