In verse 24:31,
The Qur'an says, (which means):
"And say to the believing women that they should lower their gaze and
guard their modesty, that they should not display their beauty and ornaments
except what must appear thereof; that they should draw their "khimars"
(a head cover that hangs from the top of the head down over the neck,
shoulders, etc.) over their bosoms and not display their beauty except
to their husbands, their fathers, their husbands' fathers, and their sons,
or their husbands' sons, their brothers, and their brothers' sons, or their
sisters' sons, or their women, or the slaves whom their right hands
possess, or male servants free from physical needs, or small children
who have no sense of the sexes, and that they should not strike their
feet in order to draw attention totheir hidden ornaments. O ye believers!".....
**some people call these items (such as scarves, etc.) "hijaabs", but
actually the word "hijaab" is meant to describe the FULL hijaab,
complete cover from head to toe.
Hope this clears up any misconceptions!