N Tier Architecture Application will be 4 layers which are good for creating Rich web applications. First one is Data layer in this layer all the data records ,tables, store procedure, scalar functions and tables values functions are used. All these functions are treated as in database engine, We can used Sql Server as data layer. Second is Data Access Layer which is responsible for handle all the database related tasks and queries. DAL is only one layer which work in separate mode means that if we wants to changes in database only without changes in whole web Application or website then Data Access layer is used for to do separate tasks. Third one is BLL ( Business Logic Layer ) this layer responsible for all the business logics,validations and calculations of web applications. The last one Layer is Presentation Layer is called web from layer in which all .apsx pages are have codes. The main Functionality of an this layer provide User Interference UI for gets inputs from user.