Data Access Layer which is receive a request from buisness 
object layer and speaks to database , get the result and 
return to buisness object.

All sqls and Stored procedure execution will be placed.

Hi... Data access layer is nothing but EIS(Enterprise 
Information Server)which can store the databse objects 
associated to the webapplication.

Data Access Layer or DAL in an application is the layer which 
takes care of interaction with database. In DAL , generally 
Insert, Update and Delete Queries are written. DAL sits 
between database and the Business layer.

DAL is a class which you can for talking to database. In 
this case you do not need to worry about creating DB 
connection, destroy db objects, connection pooling. 
Everything is handled by DAL for you. You only need to 
create class derived from DAL and define sored procedures 
and classes for storing result from stored procedures.

This is very convenient way of talking to DB.