Dynamic data is any information which can be attached to a certain type of content item or a page. In Sitefinity 3.x, we used to name this information as metadata, and we could insert it through a metafield.
Sitefinity expands the features related to the meta data. Now it is possible not only to add an additional information to an existing content item, but to entirely create new data types. Adding new dynamic data could be done through additional dynamic fields (meta fields in 3.x).
Adding fields through code is completely possible. It is important to note that if we add a new dynamic field, a new database column is actually created for the content type to which we the field is added. This means that all dynamic fields are stored in additional columns.
When a new data type is created through the API, a new table in the Sitefinity database is created as well. We will demonostrate this.