And as you use your Steem Power to vote other steemains the more you gain from the the upvotes that you have given.

You are right . That's what we call curation rewards . More the SP , more the voting weight and more the curation rewards.

Curation is the at of giving rewards to content creators based on own specification on the power with the help of the steem power that one possessed.

Yes voting is a part of curation . It has other components like analysing content , commenting , resteeming etc .

first day to the to at least day six.

Yes after 6 days and 12 hours there is discount of rewards with 0% at 6days and 12 hours and 100% after 7 days .

Good luck