3 Layer vs 3 Tier Architecture | Difference Between 3 Layer and 3 Tier Architecture

Before moving to understand what is difference between 3 Tier Architecture and 3 Layer architecture lets have an overview about what is Tier and What is Layer ???

The layers reside on the same machine where the tiers can reside on different machines.

Layer communicates with each other either by Value or by Reference. However the Tiers could be on different machines, so they communicate by Value only – as serialized objects.

Layer is logical separation of code and Tier is physical separation of code, In other words we can say Tiers are the physical deployment of layers. Or a Tier becomes a  Layer if it could be physically separated from the Layers it consumes.

N-Tier Architecture is a physical structuring, while a N-Layer Architecture is a logical structuring.

Now coming to 3 Layer Architecture and 3 Tier Architecture after getting an idea about Layer and Tier.

In 3 layer architecture, the Database Access Layer (DAL), Business Logic Layer (BLL) and User Interface Layer (UIL) resides as 3 different project and the output of these 3 projects (.dll file) must be together in the same server or on same machinein order for the system to run.However in 3 tier architecture, the Database Access Layer (DAL), Business Logic Layer (BLL) and User Interface Layer (UIL) reside as 3 different projects. But each of the projects can be deployed at the different server or at the different machines and distributed functionality is explored.

In 3 layer architecture DAL, BLL and UIL can work on same machine where as in a 3 Tier architecture a client in on one machine, the application Server is hosted in another machine and the database server resides in another machine i.e. Three-tieris a client–server architecture in which the User Interface, Business Logic , Data Storage and Data Access are developed and maintained as independent modules on separate platforms.

In 3 Layer we have distinct namespaces and classes for the various layes i.e. we’re only talking about logical organization of code and passing objects between layers is easy as all assemblies will run under same application in single machine.But 3 tier applications are not straight as 3 layers, because each layer will be deployed in different machines. So here, we need a mechanism to send the objects between different machines over the network hence we use technologies called Web Services, Remoting or WCF, etc. in order to implement 3 tier applications

3 Layer Architecture will improve readability and reusability, Minimizes the application changes due to impact of the changes in other layers. While 3 Tier Architecture has all advantages of 3 layer + scalability as application will be deployed in different machines so load will be shared among the tiers and scalability will increase

ASP.NET MVC 3 Interview Questions

ASP.NET MVC 3 Interview Questions

Real time Examples of oops fundamental

Oops! What an excellent concept. Nowadays in software filed any latest language has implemented, it should be partially are fully supported this oops concept. OOPs, let c with real time examples.Six important factors are using this concept are,

1. Class, 2.Objects, 3.Abstractions, 4.Encapsulation, 5.Polymorphism, and 6.Inheritance.

1. Car Vs Class

Car: Collection of several properties like staring, break, clutch, etc each things are used for particular purpose, all these properties are differ from each car like some car have power staring ,however we have called it’s a car.

Class: it’s a collection of functions and variables. The functions and variables are differing from each class. Each function is used for particular purpose however we have called it’s a class

2. Car Key Vs Object

Car Key: key is used for run the car. So many dummy keys can use for run a car.

Object: Object is used for run the class or invokes the class. So many objects can create for a single class.

3. Birds Vs Abstractions

Birds: we invented flight based on the mechanism of Birds. So flight is derived form the base of birds.

Abstraction: Abstraction is a way to remove the association of the behavior of an object with the actual details behind the scenes which implement that object's behavior. This 'abstraction' is usually accomplished through the use of base classes with virtual functions; each derived function provides the details that implement the behavior behind that abstraction.

4. Pen Vs Encapsulation

Pen: Ink is the important component in pen but it is hiding by some other material

Encapsulation: is a process of binding or wrapping the data and the codes that operates on the data into a single entity. This keeps the data safe from outside interface and misuse. One way to think about encapsulation is as a protective wrapper that prevents code and data from being arbitrarily accessed by other code defined outside the wrapper.

5. Crocodile Vs Polymorphism

Crocodile: live indifferently on land or in the water. In water it’s Moment very fast compare to land. An animal lives in different character in different place.

Polymorphism: a single function or single operator has different character in different place.

6. Human heredity Vs Inheritance

Human heredity:The genetic transmission of characteristics from parent to offspring. The sum of characteristics and associated potentialities transmitted genetically to an individual organism

Inheritance: The new classes, known as derived classes, take over (or inherit) attribute and behavior of the pre-existing classes, which are referred to as base classes(or Parent classes). It is intended to help reuse existing code with little or no modification.