Content and Property-Value Queries
Indexing Service considers a document to be an assemblage of properties, which are either text-type or value-type. (See Property Types for a description of the types of properties.) Most queries of text-type properties involve the Contents property, so these queries are often called "content queries." Queries of value-type properties are similarly often called "property-value queries."
Queries involving text-type properties or textual value-type properties are limited in comparison to queries of nontextual value-type properties. For example, queries can contain Boolean operators when they involve either type of property, but queries can contain relational operators only when they involve value-type properties. (See Property Querying for a description of properties and queries.)