Hijabs and Headscarves

Not really a get to know you question, but I wasn't exactly sure what category to put my question. As an Asian-American athiest who grew up in a Christian household, I'm not someone who had to or was presented with the idea of wearing a hijab or headscarf. I'm not very well verse on the cultural and/or religious significance it is in women who do wear them (correct me if I'm wrong, but I have also heard men are wearing them too). For those who do wear them, I would like to know what is your reason for wearing them and your feelings about wearing them? For those who wear them due to their religion, do you feel that you shouldn't have to wear or hijab or headscarf, or do you feel that it's an important part of your religion? If my question has offended anyone, I'm sorry and please know it wasn't my intention to.