The Options step in the widget wizard is where data from the dataset is bound to a presentation component. It's also the place where any configuration options can be specified.
The Basic tab on this step contains settings for the main properties on a component. These almost always include options to bind fields from the dataset to UI elements on the component. In addition to these data binding options, additional properties will be available on this tab depending on the component.
Most components have many more settings than can be set on the Basic tab. Use the Advanced tab in order to set any property available on a component using the component's JSON configuration. This feature requires familiarity with JSON formatting. A link to the documentation for a given component will be available in the heading above the JSON configuration text box as seen in the screen shot below. For more on component configuration, visit Presentation Components.
One other thing to note in the screen shot below is that spaces in JSON format need to be represented in Unicode character format \u0020.