Az-zahra Badamasi Ishaq..
Kaduna Press

Hijab literally means covering and is a type of clothing that covers a womens body.islam instructs women to cover their bodies except their hands and face from non mahram.

non mahram denotes males that are not close Family members in front of whom women must cover themselves and behave modestly.

the necessity of having Hijab can be extracted from Quranic verses and various Hadith. 

Allah most High, has stated in the Quran:
        "Tell the believing men to cast down their eyes (from indecent looks) and guard their modesty. this is purer for them. surely Allah is aware of all they do. And tell the believing women to cast down their eyes (from indecent looks) and guard their adorments save those  that are (naturally) manifest and cast their veils over their bosoms and not reveal their adorments save for their husband, father, husband's father, sons, husband's sons, brothers, brother's sons, sister's sons, their fellow women (in faith), their bondservants, their dependants (such as dullards) who do not have sexual desires, or children who do not know of womens private parts; and they must not stomp their feet in order to reveal their hidden ornaments. And repent to Allah, O believers, haply you may  attain bliss." 
these verses pertain to the Hijab of women and contain several issues that must be expounded; 
First, they ask the faithful, men and women to secure their eyes and not leer. men must not stare at women and women must not stare at men. 
sometimes, persons look at others and looking is not their purpose. At other times, people look lustfully at others for sexual pleasure; this is called leering . leering is a cause for human corruption and thus it has been forbidden. However, looking without hedonistic desires is not Haram, because it is necessity for sociability and communal living.
Next, these verses direct men and women to guard their private parts.
then they address women and declare:
    Do not reveal your adornments save those that are manifest."
Zinat means adornment. there are various types of adornment. Fist are those that are detached from the body, such as earrings, necklaces, rings, hairclips, bracelets, and decorative clothes. Second are those that are applied to the body, such as eyeliner. nail polish, and hair color.  Adornment spoken of in this verse encompasses both these types. women are advised to eschew revealing their adornments for non muhram men and thus prevent drawing the attention of men and arousing their sexual inclinations.
the next statement gives women permission to refrain from hiding their evident adornments that are naturally obvious such as specific type of natural eyeliner, eyebrow coloring, henna, rings, veil coloring, robes, and shoes. since women are part of the society and have social responsibilities, naturally, non muhram men see will certainly see their face, hands, and obvious adornments and covering these would be difficult. for this reason, islam gives them permission to perform their duties without covering these.  

some several important ethical and Islamic issues are derived from this verse ..
1. Men and women (who aren't married to each other) must abstain from visual indulgence and looking at each other in a lustful manner. people must not look at one another for sexual pleasure.

2. women must not reveal their hidden adornments to men

 3. women are obligated to wear their veil or headscarf in such a manner that their ears, earrings their neck and the surrounding area. and their breasts are completely covered.

4. women are not required to cover their obvious adornments.

5. in order to honor public modesty and counteract moral corruption, women are advised to tread softly so the sounds of their steps do not cause corruption in men.
5. women are not required to cover their obvious adornments.

Hijab isn't just a peace of clothe

Wearing hijab doesn’t mean you are perfect or righteous. It’s a wonderful identity as a Muslimah (a humble servant/slave of Allah).
Wearing hijab is an act of obedience to Allah.
Wearing hijab is an act of worship to Allah SWT.
Wearing hijab is a sign of self-respect & shyness (hayah). 
Wearing hijab is a sign that you have faith in Allah (iman).
Wearing hijab is a sign that you fear Allah (taqwa).
Wearing hijab is an obligation not a fashion.
Wear your hijab properly my sisters..