Some content items can be rated with a number of stars, if your organization uses ratings. This helps other users judge whether the item is considered useful by the wider community. Ratings are indicated in each record when it is individually displayed
When you view a single record, you can work with ratings in the following ways, if your role allows:
Click a number of stars in the top row to rate the content, from 1 star (low) to 5 stars (high). The display also indicates the Overall number of stars that have been applied by all users and the average (for example: Average of 5 ratings: 3.0 stars). You can only rate an item once. However, you can re-rate the comment later, if you change your mind. To remove a rating, click the removal button at the left of the rating control.
Choose Social>Moderate (or click the Moderate Social Content button) and use the resulting screen to remove one or more ratings from the record, if your permissions allow.
Additionally, you can search by ratings if the Rating search control has been added to a search screen. For more information, see Searching for Social Content.