Artifacts represent the pieces of information relevant to the model, and individual elements within a process. There are three artifact types, they are annotations, groups, and data objects. All three were used to augment and describe BPMN processes.
Annotations allow modeler to describe the additional flow parts of a model/notation.
Groups organize tasks/processes that have significance in the overall process.
BPMN Group Annotation
Data objects represent data placed into a process, data resulting from a process, data that needs to be collected, or data that needs to be stored.
- BPMN Data Input
The data input symbol represents the data requirements that takes in a business process
- BPMN Data Output
The data output symbol demonstrates the information/data produced, as the result of the business process.
- BPMN Data Collection
The data collection symbol signifies the information collected within a business process.
- BPMN Data Storage
The data storage symbol represents, the ability to store/access data that is associated with the business process.
Hope this helps!