 managing content structure what types of data does a site have  there are four main types of data content is the information text images etc meant to be displayed to website visitors configuration is data that defines how the content is displayed some configuration such as field labels may also be visible to site visitors state is temporary data about the state of your site such as the last time the system cron jobs ran session is a subset of state information related to users interactions with the site such as site cookies and whether or not they are logged in what is a content entity  a content entity  or more commonly  entity  is an item of content data which can consist of text html markup images attached files and other data content entities are grouped into entity types  which have different purposes and are displayed in very different ways on the site most entity types are also divided into entity subtypes  which are divisions within an entity type to allow for smaller variations in how the entities are used and displayed for example the content item entity type that stores pagelevel content is divided into content type subtypes the content block entity type has block types  but the user entity type for user profile information does not have subtypes what is a field  within entity items the data is stored in individual fields  each of which holds one type of data such as formatted or plain text images or other files or dates fields can be added by an administrator on entity subtypes so that all entity items of a given entity subtype have the same collection of fields available and they can be singlevalued or multiplevalued when you create or edit entity items you are specifying the values for the fields on the entity item what is a reference field  a reference field is a field that stores a relationship between an entity and one or more other entities which may belong to the same or different entity type for example a content reference field on a content type stores a relationship between one content item and one or more other content items what field types are available  the following field types are provided by the core system and core modules many more are provided by contributed modules boolean number provided by the core system stores true false values and numbers comment provided by the core comment module allows users to add comments to an entity date timestamp datetime module stores dates and times date range datetime range module stores time date periods with a start and an end email core system stores email addresses link link module stores urls and link text list options module stores values chosen from predefined lists where the values can be numbers or text see section below for more on list fields reference core system stores entity references see section above telephone telephone module stores telephone numbers text text module stores formatted and unformatted text see section below for more on text fields what settings are available for list field types  list fields associate predefined keys  or value codes with labels that the user sees for example you might define a list field that shows the user the names of several locations while behind the scenes a location code is stored in the database each list field type corresponds to one type of stored key for example a list integer  field stores integers while the list text  field stores text strings once you have chosen the field type the main setting for a list field is the allowed values list which associates the keys with the labels what types of text fields are available  there are several types of text fields with different characteristics text fields can be either plain or formatted  plain text fields do not contain html while formatted fields can contain html and are processed through text filters  these are provided by the core filter module if you have that module enabled see the related topic below on filters for more information text fields can also be regularlength with a limit of 255 characters or long  with a very large character limit and long formatted text fields can include a summary attribute all possible combinations of these characteristics exist as text field types for example  text plain  and text formatted long with summary  are two examples of text field types what is a formatter  a formatter is a way to display a field most field types offer several types of formatters and most formatters have settings that further define how the field is displayed it is also possible to completely hide a field from display and you have the option of showing or hiding the field s label when it is displayed what is a widget  a widget is a way to edit a field some field types such as plain text singleline fields have only one widget available in this case a singleline text input field other field types offer choices for the widget for example singlevalued list fields can use a select or radio button widget for editing many widget types have settings that further define how the field can be edited managing content structure overview besides the field modules listed in the previous section there are additional core modules that you can use to manage your content structure the core node comment content block custom menu links user file image media taxonomy and contact modules all provide content entity types the core field ui module provides a user interface for managing fields and their display on entities the core layout builder module provides a more flexible user interface for configuring the display of entities the core filter responsive image and path modules provide settings and display options for entities and fields depending on the core and contributed modules that you currently have installed on your site the related topics below and other topics listed on the main help page see help will help you with tasks related to content structure additional resources concept types of data drupal user guide  planning your site drupal user guide  concept reference fields drupal user guide  