User accounts who commit their STEEM to a thirteen-week vesting schedule, are provided special benefits within the platform. STEEM that has been committed to a thirteen-week vesting schedule is called Steem Power (SP). When users vote on content, their influence over the distribution of the rewards pool is proportional to the amount of Steem Power that they have. Users with more SP have more influence on the distribution of rewards. This means that SP is an access token that grants its holders exclusive powers within the Steem platform namely:
Steem Power holders also earn new tokens based on the balance of SP that remains vested. SP holders are paid 15% of the yearly inflation. The amount of new tokens they receive is directly proportional to the amount of SP they hold relative to the total amount of vested SP across all users.
Transferring from STEEM to SP is referred to as “powering up,” while transferring from SP to STEEM is referred to as “powering down”. When STEEM is powered up, it is converted to VESTS. SP that is powered down is returned to the user over a period of thirteen weeks, via 13 equal weekly payments, starting one week after the power down is initiated.