Voting power is the weight a participant’s vote carries in Cardano governance. Votes are not counted per person but per ada: every holder’s stake contributes voting power, and outcomes are decided by the share of stake voting each way, not by the number of voters.
A DRep’s voting power is the sum of all stake delegated to them by ada holders, so it changes as people delegate to or away from them. An SPO’s voting power is the stake delegated to their pool. Whether a governance action passes depends on the share of participating voting power that votes Yes, with thresholds set per action type by protocol parameters; stake delegated to Abstain is left out of that calculation.
The DRep directory shows each DRep’s current voting power and lets you compare how concentrated or spread out delegation is.