> For the complete documentation index, see [llms.txt](https://docs.gapvelocity.ai/webmap/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.gapvelocity.ai/webmap/general/backend/dcp-desktop-compatibly-platform/library-bundles/bundle-dto/dto-data-transfer-objects.md).

# DTO: Data Transfer Objects

A Data Transfer Object (DTO) is a plain C# object used by WebMap to communicate the necessary data from between the different layers, typically the data sent in them is the following:

* Visual properties needed to render a control component and dictated its behavior in the UI. Properties such as Visible, Enabled, BackColor, among many others.
* Event handler’s information, similar to what can be found in a desktop control the WebMAp controls implement the required events that need to be bound in order to be able to execute any action, a DTO has the responsibility of indicating which are the events that are needed set.
* Object references, a DTO is a plain object design to hold only value types (string, Boolean, numeric, dates, etc.), however, the objects that they represent may have references to other complex objects, such as a Parent control, that need to be sent as well in other to represent objects hierarchy.

A DTO class does not have any kind methods, they serve as a contract between the server and the client layers. If a model property needs to be sent to the front-end it must necessarily be included in the DTO specification.