Different communities have their different reputation each. They independent each other.

Alright, but if you've checked previous articles/white paper you would've get clarity on every confusions. But no worry; it's not a problem at all. Reputation is gained as you contribute in a platform. You'll not get direct profit from any of these rep. But you'll have more weight in your votes. Thank you so much being with us & making the community strong.

i also have that doubt then i realized that repotation is different for every community

Different Communities have different Reputation brother. If you want to boost your reputation, you need to create positive articles and comments. Good luck