Reputation represents your voting power (how much influence you have in decision-making) within a particular DAO. Someone who has 10 Reputation points has double the influence of someone with 5 Reputation points.
Technically, Reputation is a score each DAO tracks for everyone who can vote in that DAO. Reputation cannot be transferred to others, and the amount of overall reputation is not fixed.
There are a number of ways to gain and lose Reputation, including passing proposals. You can read more about DAOstack’s initial reputation protocol in this article.