In terms of fashion and tradition, I always love islamic culture. Especially the shawl, golden glittering dress and the hijab for women. Hijab, from the arabic word which means "cover". 
For non-Muslims, it's synonymous with the headscarf, but it can be used to describe modesty. Those who cover up do so because of passages in the Quran and other Muslim scriptures. 

 The question is why do Muslim women need to use hijab? Simply the answer to that question is that, Muslim women followed Allah's command from the Quran. Here's a few line, "O Prophet, tell your wives and daughters and the believing women to draw their outer garments around them (when they go out or are among men). That is better in order that they may be known (to be Muslims) and not annoyed..." [Noble Quran 33:59]