Styles control how features appear on a map. Default styles are applied to features. When you add point and polygon features to the map, they appear with default symbol, line, and fill styles. Polylines are given a default line style. Each layer is given a distinctive color. For example, polygons are filled with a color that is different from other polygon layers that are already in the map. Change the default styles as needed.
This illustration shows typical styling for polygons, lines, and points.
You can specify the scale ranges at which a feature is visible, set line color, and add labels. To specify styles for a layer, you define a style for a scale range. 0 - Infinity is the default scale range. Add narrower scale ranges as you define styles to define how the data appears at various scales. For example, you could create one scale range that displays roads with thick lines when you zoom in, and create a second scale range that displays roads with thin lines when you zoom out.
You can change styles using the Style Editor, or the Style tab that appears in the ribbon when you select a feature layer in the Display Manager.
You can also create a theme that displays data in varying styles to indicate different values.