In Apache Solr's managed-schema.xml, it is an attribute that can be specified for field types and field definitions. The default is stored="false", which declares that no value will be stored for that field. Not storing a value for a field means that when displaying a document (for example, when displaying a document in a search results list), the information for that field will not be displayed (cannot be displayed).
For example, let's consider the schema design for book search in a library. We want to display the book title (title) and author name (author) in the search results list, so we set stored="true" for these fields. On the other hand, if we don't need to display the 'reading of the author's name' (author_reading), then we set stored="false", resulting in the following:
<field name="title" type="text_ja" indexed="true" stored="true"/>
<field name="author" type="text_ja" indexed="true" stored="true"/>
<field name="author_reading" type="string" indexed="true" stored="false"/>
