What is the wisdom and benefit behind a girl covering her head, and what are the consequences of not covering it?

A woman covers her hair in compliance with Allah's command, which carries great wisdom, including preserving her honor and protecting her from harm, as substantiated by His (the Almighty’s) saying: "That is more suitable that they should be known and not be abused." Hijab, therefore, protects women from the covetousness of the wicked. The Prophet, peace and blessings be upon him, warned women who display their adornment (tabarruj) of Hellfire, describing them as "women who are clothed yet naked, inclining [to evil] and inclined [to it], their heads like the humps of camels, leaning to one side. They will not enter Paradise nor smell its fragrance." Islam desires a pure society, and a woman's uncovering her hair increases temptation and leads to indecencies. A woman should know that all of Allah's commands are good, and Islam is submission to Allah's command and obedience, even if one does not know the wisdom behind it.