Both Endeca properties and dimensions:

Although Endeca properties and Endeca dimensions share many characteristics, only dimensions can be used for guided navigation. The MDEX Engine generates indexes based on your mappings, and only indexes for dimensions can be used for navigation.

Thus, when you map a source property to an Endeca property or dimension, consider whether the value of that property is suitable for use as a navigation term. If it is suitable, map it to an Endeca dimension. If it is not suitable, map it to an Endeca property. For example, a source property whose value is "Wine Type" is useful for navigation because it enables you to identify a set of wines according to type: red, white, sparkling, and so forth. Source properties that contain this type of information should be mapped to Endeca dimensions.

On the other hand, a property whose value is a long description of a wine is not suitable for use as a navigation term, and for this reason should be mapped to an Endeca property rather than to an Endeca dimension. For example, end users do not query for wines that are "intense, with complex earthy pear, fig, melon, citrus and hazelnut flavors that are remarkably elegant and sophisticated." This type of information is useful to display when the user has navigated to the record, and source properties that contain this type of information should be mapped to Endeca properties.

Endeca properties often contain more specific information about a record than dimensions. For example, a Price Range dimension is useful for navigation—give me all the bottles of wine that cost between $10 and $20 dollars—but it is the exact price of each bottle that you want to see when looking at the individual records. A common implementation for this type of application uses a Price Range dimension for navigation and a Price property that is displayed when a bottle’s record has been located.