What is an Upvote on Reddit?
An upvote if an action available on Reddit, similar to a "like," in which an user upvotes a thread or comment posted by another user by pressing an upvote button with an icon of a upward arrow. The opposite action is a downvote. The total number of points a post has, the number of upvotes minus the number of downvotes, also called the karma, is displayed next to the upvote and downvote buttons.
On Imgur
Imgur also shares the same concept of upvotes as Reddit.