Dataports exist as separate object types only in the two-tier (Classic) client. In the Role Tailored Client, the functions handled by Dataports in the Classic Client are handled by XMLports.
Dataports are specialized objects designed to export and import data between the two-tier NAV database (whether Classic or SQL Server) and external text files. Dataports allow for a limited set of external data formats, generally focused around what are commonly referred to as "comma separated value" (also known as "comma-delimited" or csv) files. The delimiters don't actually have to be commas, that's just the common name for this file structure.
Dataports can contain C/AL logic that applies to either the importing or the exporting process (or both). The internal structure of a dataport object is somewhat similar to that of a report object combined with a table object. Dataports are driven by an internal read-then-process loop similar to that in reports. Dataports contain field definitions that relate to the specific data being processed.
Dataports are relatively simple and quite flexible tools for importing and exporting data. The data format structure can be designed into the dataport as along with logic for accommodating editing, validating, combining, filtering, and so on of the data as it passes through the dataport. Dataports can be accessed directly from a menu entry, in the same fashion as forms and reports in the Classic Client.