|The MVC Pattern|
|The 3-tier Architecture|
- Presentation Tier - responsible for rendering the User Interface
- Business Tier (or Logic Tier) - responsible for processing the business rules or logic
- Data Tier - responsible for interacting with the data storage system
The MVC implemented in a three-tier architecture
|The MVC - Three Tier Hybrid|
Some important aspects of this diagram include is the separation of data reads from writes. Writes take considerably more data storage resources than do reads, so separating these into different physical data stores can have huge benefit. It should also identified that the modules for the business and data logic can be numerous. And these exist for maintainability and scalability purposes. It is also reasonable that the Model may access the Data Tier directly without going through a Business Tier module.
Why the hybrid?
The MVC pattern does not describe how to best design the data access and how to manage the complexity that can occur within the business and data tiers. As the internet has become more open and further entrenched in business processes, the demand to access the business tier without the presentation tier has increased. The creation of Business Tier modules allows for other approaches (such as REST) to access business logic from other sources, enabling business-to-business interactions and innovations.
if you would like to read a non-technical post describing the MVC pattern within a three-tier architecture, follow this link; http://criticaltechnology.blogspot.ca/2011/10/mvc-in-three-tier-architecture.html