Crystal reports need database drivers to connect to connect a data source for accessing data and showing into a report. VB.Net support two methods to access data from data source and publish it .
(i) These two methods are The Pull Model: When this model is used to access data from the data source, the data driver directly from data source. This model does not require a dataset means this model does not require the programmer to write any additional code. The crystal report creates and manages the SQL commands for connecting to the data source and retrieving data from it.
Crystal Report-------------Data---------------Data source