When you upvote a post/comment, you are recommending that more people ought to read and engage with it.
When you agree vote a post/comment, you are communicating that you endorse its conclusions/recommendations.
Symmetrically, if you downvote a post/comment you are recommending against engaging with it.
And similarly, if you disagree vote a post/comment you are communicating that you don’t endorse it’s conclusions/recommendations.
Upvotes determine the order of posts of comments and determine which comments are automatically hidden, so have a measurable effect on how many people read them.
Agree votes AFAIK do not affect content recommendations, but are helpful to understand whether there is community support for a conclusion, and if so in which direction.
Quick guide on the agree/disagree voting system:
When you upvote a post/comment, you are recommending that more people ought to read and engage with it.
When you agree vote a post/comment, you are communicating that you endorse its conclusions/recommendations.
Symmetrically, if you downvote a post/comment you are recommending against engaging with it.
And similarly, if you disagree vote a post/comment you are communicating that you don’t endorse it’s conclusions/recommendations.
Upvotes determine the order of posts of comments and determine which comments are automatically hidden, so have a measurable effect on how many people read them.
Agree votes AFAIK do not affect content recommendations, but are helpful to understand whether there is community support for a conclusion, and if so in which direction.