You can reward other Community users for their contributions by voting for (or "liking") their questions or answers. To do it, click Like below the post.
To vote for a comment, hover over the comment until you see the links to the right of the commenter's name, then click Like.
You can vote on as many posts as you want.
If another member makes a particularly helpful or insightful post, you can give that member reputation points. Click Reward User below the post to display the Reward User popup window.
The number of points you can award to another user (through the Reward user link below a post) is equal to your reputation score minus points you've already awarded. As your reputation score increases with your Forum participation, your available points increase.