Difference between ExecuteReader,ExecuteScalar and ExecuteNonQuery

• ExecuteReader: Use for accessing data, it provides a forward-only, read-only, connected recordset.
• ExecuteScalar: Use for retriving Single value i.e 1 row 1 column value. Eg: for retriving aggregate function. Its faster than other ways fo retriving a single value from Database
• ExecuteNonQurey: Use for data manipulation, such as Insert, update and delete