You can stake HIVE as Hive Power, it is usually referred as powering up HIVE or staking HIVE.
Half of your earnings from publishing automatically staked, half you get in liquid tokens. All your curation earnings staked automatically. The more stake you have more curation reward you earn and you can reward others more as well.
Thank you very much, I was with this doubt for some time and did not know how the stake system worked