The 'like' function in the Community is how you can let someone know that you appreciate their contribution to a discussion. You will find a thumbs up icon at the bottom of each post here in the Community, which when clicked will add a ‘like’ to the user’s post. Likes work very similarly to that of Facebook, Twitter and other social networks – if you are familiar with them. Some notes:
You can only give one like per post
Giving out likes is fun, but try not to go bananas! Likes are to be used when you've found something useful
Likes are ranked on the front page. See if you can get to the top of the leaderboard by contributing the most useful information!