Yes, men are at the front and women are at the back. Some people wonder why are the two genders are not mixed in Islam and have a miss understanding about it. The two genders (men and women) are naturally attracted to each other. This attraction will lead to sexual relationships. This will weaken the society and mix up people (no body will know for sure who is his father) and this is a disaster. Add to this crimes, emotional problems, low reproduction rates, etc. This topic is too long to discuss now but you can compare two different societies take for example the Saudi and the American, you can see the difference.
It is not like Islam is against sex or the interaction between men and women but we in Islam have some rules about this to preserve both genders. Sex can be done with marriage, and believe me it is better by all the means.