Please refer to the following URLs to know the differences between DataSet and DataReader,http://onlydifferencefaqs.blogspot.in/2012/07/adonet-difference-faqs-1.htmlhttp://onlydifferencefaqs.blogspot.in/2012/08/difference-between-datareaderdataset.html

datareader is the read only forword Acess the data.
it acn be faster than the dataset.
it can be retrive the data from database only one record.
for examples :if you have ten pages by using this it is going only forword only like first page to second page and third page --etc like that .but it can not be come back like second page to first page .
dataset is retrive the data from database .
by using dataset you can retrive the data from multiple tables.
it can be slower than the datareader.
dataset  can access the data from xml files also.

There are lot of differences between the Dataset and DataReader. Few are:

1. DataReader is forward  only and read only but Dataset is not.
2. In Dataset we can edit the records but in Datareader it is not possible.
3. DataReader is more fast then dataset.

There are lot of differences between the Dataset and DataReader. Few are:

1. DataReader is forward  only and read only but Dataset is not.
2. In Dataset we can edit the records but in Datareader it is not possible.
3. DataReader is more fast then dataset.