# Tags

Tags are named variables that can be created by the user to store data, and can be inputs (read to) or outputs (written from). In programming terms, they are similar to global variables. The data stored in a tag can be accessed and shared throughout the entire application.

Tags are the primary way Cognex Designer shares information between the different areas of the application, and they are usually identified by the '$' character.

Tags can also contain an array of data, such as an array of integers or an array of blobs. These types of tags can be created by accessing the Complex Type Selector dialog, when editing the tag's Data Type (using the Data Type Selector), while in the Tag Manager.

Note: For more information about creating an array data type for a tag, see the Creating an Array with the Complex Type Selector Dialog topic.