Each field has a field data type , or field type . This type indicates the kind of data the field contains, such as strings or boolean values, and its intended use. For example, you can index strings to both text and keyword fields. However, text field values are analyzed for full-text search while keyword strings are left as-is for filtering and sorting.

Field types are grouped by family . Types in the same family have exactly the same search behavior but may have different space usage or performance characteristics.

Currently, there are two type families, keyword and text . Other type families have only a single field type. For example, the boolean type family consists of one field type: boolean .

In Elasticsearch, arrays do not require a dedicated field data type. Any field can contain zero or more values by default, however, all values in the array must be of the same field type. See Arrays .

It is often useful to index the same field in different ways for different purposes. For instance, a string field could be mapped as a text field for full-text search, and as a keyword field for sorting or aggregations. Alternatively, you could index a text field with the standard analyzer , the english analyzer, and the french analyzer .

This is the purpose of multi-fields . Most field types support multi-fields via the fields parameter.