What is a a snood?
A snood is nothing but a headgear worn by women to cover their long flowing hair. You can equate it to a hood that covers the back of the head. The band covers the top of the head going behind the ears and supports the clothing under which the long hair is rolled into. You can find many variations of a snood in cloth or yarn, which can be selected depending on your tastes and preferences.
A snood or headgear is being used since the middle ages, cutting across religions and cultures. However, in modern times, it is associated with orthodox Jewish married women who wear it under the law. Jewish women mainly wear it after marriage, but you can find many instances where unmarried women too wearing them out of interest in their religion. Wearing of snoods has been discarded by Jewish women a generation ago, but occasionally you can find them wearing which is not surprising.
There is difference of thought on why a snood must be used by women. Some believe the practice must be abandoned, while some others vociferously support using them. Even the Rabbis are divided and their interpretation on wearing snoods differs. Some preach wearing them, while some others are more tolerant and leave it to the women to wear, if they are interested. From this, we can conclude that it is not mandatory to wear snoods.
In the early days, women were forced to wear snoods as it was felt that women's long flowing lovely hair is a sensual attraction for men and by covering the hair, sexual instincts are not aroused in men looking at the women. In the days when sensual women's parts are not shown in public, it is considered necessary to cover women's hair with snoods.