Definition - What does DataReader mean?
A DataReader is a specific type of software built into parts of the Microsoft .NET (pronounced dot net) Framework. This object allows for reading data from a data source.
Techopedia explains DataReader
The .NET Framework includes a suite of software called ADO.NET. In this general category, the DataReader is designed to parse a Tabular Data Stream from SQL or from a continuous stream of data. Taking an unbuffered stream of data, the DataReader can use a strong or weak typing approach to process that data. This involves how the program reads field values. Stronger typing can cause problems with types that do not fit a particular result. Weak typing can be more versatile. Using a DataReader, developers can access and modify data in relational databases or other systems.