Voting weight is the percentage of a vote given on a post or comment on Hive. This is on a scale of 100.
Each vote can be altered based upon the desire of the curator. Most applications allow for 1%-100%. The weight of each vote will affect the voting power of an account. When a higher vote is given, it will use up more of the daily voting power.
This is rechargeable, at a rate of 20% per day.
Giving a vote with a higher voting weight also affects the rewards. The value of the vote, in $HIVE and HBD, will increase as the voting weight is raised.