What is the difference between tier and layer

Logical layers help you organize your code better. For example, an application can have the following layers. The above three layers reside in their own projects, maybe 3 projects or even more. When we compile the projects we get the respective layer DLL. So we have 3 DLLs now. Depending upon how we deploy our application, we may have 1 to 3 tiers. As we now have 3 DLL's, if we deploy all the DLLs on the same machine, then we have only 1 physical tier but 3 logical layers.

So, Layers are a logical separation and Tiers are a physical separation. We can also say that tiers are the physical deployment of layers. For example, one machine hosting the Web Site itself the Presentation layer , another machine more secured hosting all the more security sensitive code real business code - business layer, database access layer, etc.

There are so many benefits to implement a layered architecture. This is tricky and properly implementing a layered application takes time. I've found a definition that says that Layers are a logical separation and tiers are a physical separation.

In plain english, the Tier refers to "each in a series of rows or levels of a structure placed one above the other" whereas the Layer refers to "a sheet, quantity, or thickness of material, typically one of several, covering a surface or body". Layer is a logical unit , how to organize the code. Tiers represent the physical separation of the presentation, business, services, and data functionality of your design across separate computers and systems. Layers are the logical groupings of the software components that make up the application or service.

They help to differentiate between the different kinds of tasks performed by the components, making it easier to create a design that supports reusability of components. Each logical layer contains a number of discrete component types grouped into sublayers, with each sublayer performing a specific type of task. In this scenario, the client and server may exist on the same machine, or may be located on two different machines.

Figure below, illustrates a common Web application scenario where the client interacts with a Web server located in the client tier. This tier contains the presentation layer logic and any required business layer logic.

The Web application communicates with a separate machine that hosts the database tier, which contains the data layer logic. Layering helps you to maximize maintainability of the code, optimize the way that the application works when deployed in different ways, and provide a clear delineation between locations where certain technology or design decisions must be made. Placing your layers on separate physical tiers can help performance by distributing the load across multiple servers.

It can also help with security by segregating more sensitive components and layers onto different networks or on the Internet versus an intranet. Layers are logical separation of related-functionality[code] within an application, Communication between layers is explicit and loosely coupled. Tiers are Physical separation of layers [which get hosted on Individual servers] in an individual computer process. Maintainability : Web designer can change the View-code, with out touching the other layers on the other tiers.

I like the below description from Microsoft Application Architecture Guide 2. Layers describe the logical groupings of the functionality and components in an application; whereas tiers describe the physical distribution of the functionality and components on separate servers, computers, networks, or remote locations. Although both layers and tiers use the same set of names presentation, business, services, and data , remember that only tiers imply a physical separation.

Yes my dear friends said correctly. The Language Level symbol shows a user's proficiency in the languages they're interested in. Setting your Language Level helps other users provide you with answers that aren't too complex or too simple. Sign up Sign in. English US. Question about English US. What is the difference between layer and tier and level? Feel free to just provide example sentences. Report copyright infringement.

Improve this question. Wolper H. Wolper 1 1 silver badge 4 4 bronze badges. What do the dictionaries say? MetaEd, I did try to find answers on the web for a while. Only after feeling the frustration of not being able to find answers I posted the question here.

Yet, I didn't feel like "I search the web to no avail" to indicate my research would have helped make the question clearer.

Add a comment. Active Oldest Votes. Improve this answer. So Layered architecture, enables us to secure portions of the application behind the firewall and make other components accessible from the Internet. Layered architecture also helps us to test the components independently of each other. There might be a negative impact on the performance as we have the extra overhead of passing through layers instead of calling a component directly.

The development of user-intensive applications can sometimes take longer if the layering prevents the use of user interface components that directly interact with the database. The use of layers helps to control and encapsulate the complexity of large applications but adds complexity to simple applications.

In this article, I try to explain the difference between layers and tiers in an application. I hope you enjoy this article and understand the difference between Layers and Tiers in an application.