# Module Documentation: eml-entity | Back to EML Contents

### The eml-entity module - Entity level information within datasets

The eml-entity module defines the logical characteristics of each entity in the dataset. Entities are usually tables of data (eml-dataTable). Data tables may be ascii text files, relational database tables, spreadsheets or other type of tabular data with a fixed logical structure. Related to data tables are views (eml-view) and stored procedures (eml-storedProcedure). Views and stored procedures are produced by an RDBMS or related system. Other types of data such as: raster (eml-spatialRaster), vector (eml-spatialVector) or spatialReference image data are also data entities. An otherEntity element would be used to describe types of entities that are not described by any other entity type.

The eml-entity module, like other modules, may be "referenced" via the <references> tag. This allows an entity document to be described once, and then used as a reference in other locations within the EML document via its ID.

## Module details

Recommended Usage: | This module is used to describe data entities.
Stand-alone: | Only when 'otherEntity' is used.
Imports: | eml-documentation, eml-coverage, eml-physical, eml-methods, eml-attribute, eml-resource, eml-constraint, eml-text
Imported By: |
View an image of the schema: | eml-entity image

## Element Definitions:
#### otherEntity | This element has no default value.
Content of this field: | Description of this field:
Type: OtherEntityType
| The other entity element is a descriptor of a not-otherwise-defined entity in the dataset, identified by its name. The element can contain information about the entity's basic identity, its temporal, geographic and taxonomic coverage, and its type. Example(s): Photograph of rocky intertidal plot 12 from Santa Cruz Island
#### attributeList | This element has no default value.
Content of this field: | Description of this field:
Type: att:AttributeListType
| The list of attributes associated with this entity. For more information see the eml-attribute module.
#### constraint | This element has no default value.
Content of this field: | Description of this field:
Type: con:ConstraintType
| Description of any relational constraints on ' this entity. For more information see the eml-constraint module.
#### entityType | This element has no default value.
Content of this field: | Description of this field:
Type: res:NonEmptyStringType
| The entityType field contains the name of the entity's type. The entity's type is typically the name of the type of data represented in the entity, such as "photograph". This field is used only if this is an 'other' entity and you want to specify the kind of "other" entity this is. Example(s): Photograph
#### alternateIdentifier | This element has no default value.
Content of this field: | Description of this field:
Attributes: | Use: | Default Value:
system | optional
| An additional, secondary identifier for this entity. The primary identifier belongs in the "id" attribute, but additional identifiers that are used to label this entity, possibly from different data management systems, can be listed here. Example(s): VCR3465
#### entityName | This element has no default value.
Content of this field: | Description of this field:
Type: res:NonEmptyStringType
| The name identifies the entity in the dataset: file name, name of database table, etc. Example(s): SpeciesAbundance1996
#### entityDescription | This element has no default value.
Content of this field: | Description of this field:
Type: res:NonEmptyStringType
| Text generally describing the entity, its type, and relevant information about the data in the entity. Example(s): Species abundance data for 1996 at the VCR LTER site
#### physical | This element has no default value.
Content of this field: | Description of this field:
Type: phys:PhysicalType
| Information on the physical format of this entity. Each logical entity can be serialized in one or more physical formats, which can be described here. For each physical format, provide a "physical" element that describes the format and how to obtain that version. Two physical elements MUST describe the same entity precisely (i.e., after obtaining and parsing the physical data stream described under each physical element, one MUST end with an identical logical entity). For more information see the eml-physical module.
#### coverage | This element has no default value.
Content of this field: | Description of this field:
Type: cov:Coverage
| Information on the geographic, spatial and temporal coverages used in this entity. Please see the eml-coverage module for more information.
#### methods | This element has no default value.
Content of this field: | Description of this field:
Type: md:MethodsType
| Information on the specific methods used to collect information in this entity. Please see the eml-methods module for more information. Example(s):
#### additionalInfo | This element has no default value.
Content of this field: | Description of this field:
Type: txt:TextType
| This field provides any information that is not characterized by the other entity metadata fields. Example(s): Multiple sampling events represented
## Attribute Definitions:
#### id
Type: res:IDType Use: optional
#### system
Type: res:SystemType Use: optional
#### scope
Type: res:ScopeType Use: optional Default value: document
#### system
Type: res:SystemType Use: optional | The information management system within which this identifier has relevance. Generally, the identifier would be unique within the "system" and would be sufficient to retrieve the entity from the system. The system is often a URL or URI that identifies the main entry point for the information management system. Example(s): http://knb.ecoinformatics.org/knb/
## Complex Type Definitions:
#### OtherEntityType |
Content of this field: | Description of this field:
Elements: | Use: | How many:
A choice of (
A sequence of (
EntityGroup |  |
A sequence of (
attributeList | optional |
constraint | optional | unbounded
entityType | required |
)
)
OR
res:ReferencesGroup |  |
)
Attributes: | Use: | Default Value:
id | optional
system | optional
scope | optional | document
## Group Definitions:
#### EntityGroup |
Content of this field: | Description of this field:
Elements: | Use: | How many:
A sequence of (
alternateIdentifier | optional | unbounded
entityName | required |
entityDescription | optional |
physical | optional | unbounded
coverage | optional |
methods | optional |
additionalInfo | optional | unbounded
)
| The EntityGroup defines the common structure for descriptions of any type of entity, including the name and attributes of the entity. The term entity is used in the sense of an entity in a relational model. The most common entity is a table, something with columns and rows, but can also represent an image or other type of data. See 'eml-attribute' for descriptions of the required attribute fields.

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