C#

A   stream   is an object used to transfer data. There is a generic stream class   System.IO.Stream , from which all other stream classes in .NET are derived. The   Stream   class deals with bytes. The concrete stream classes are used to deal with other types of data than bytes. For example: The  FileStream  class is used when the outside source is a file MemoryStream  is used to store data in memory System.Net.Sockets.NetworkStream  handles network data Reader/writer streams such as  StreamReader  and  StreamWriter  are not streams - they are not derived from  System.IO.Stream , they are designed to help to write and read data from and to stream!