The value style allows you to control how individual features are rendered by matching on a value in the attribute data. For example you may have a feature layer that represents different soil types in your area. With a value style you can create a matching value item for one or all of the different soil types. This gives you the ability to render each soil type differently on the map even though all of the soil type features are on the same feature layer.
Name - Sets the name of the value style.
Column Name - Sets the column in the attribute data that you want to match on.
Value Items - One ore more value items can be added to a value style. For each value item you will be able to define a style to control how you want to render the features that match this value. You can create value items in one of two ways:
Add New Button - The Add New button will add a new item in the value items grid. You can then set the Matching Value column
Auto Generate Button - The Auto Generate button will analyze the feature layer and get all of the distinct values for the column you have selected. It will then automatically create and populate a value item for each distinct value in the value items grid.
Each Value Item listed will have an area, line or point style associated with it to represent the feature(s) that have a Matching Value. In that table, you will see the Count of how many features in your layer match with the Matching Value. If you want to change the appearance of the associated style, you can select the style under the Matching Value in the Styles List on the left.