MVC architecture separates applications into the Model, View, and Controller layers. Below is the converted Markdown version of your post.
In software engineering, MVC is a long‑standing architectural pattern that divides an application into three interconnected components: Model, View, and Controller. Though it originated in Smalltalk, it’s widely used today across frameworks like Spring (Java), Django (Python), Rails (Ruby), Angular (MVVM variant), and React (with supporting libraries). Here's how each piece works — and how these concepts map to a React codebase.
Model: The Data and Business Logic
The Model is responsible for anything data‑centric. In React applications, this layer is often implemented with tools like Redux, MobX, or the Context API.
What the Model manages
- Database Records — retrieving, storing, and updating structured or unstructured data.
- HTTP Requests/Responses — calling APIs and handling returned data.
- Data Transformation Logic — reshaping or filtering data for display.
- Business Rules — validations and constraints such as “a user must verify email before purchasing.”
View: User Interface and Presentation
React components make up the View, controlling how information is visually rendered. The View should focus solely on presentation, not business logic.
What the View handles
- HTML structure that defines layout.
- CSS styling rules.
- Templated Data injected through JSX and component state.
Controller: Mediator for Model and View
React does not have a formal “Controller,” but several patterns serve this role:
- Custom Hooks
- Higher‑Order Components (HOCs)
- State management libraries
What the Controller manages
- User Actions — clicks, form submissions, keyboard interactions.
- Application State — interpreting events and updating Model state.
- View State — controlling what is shown and how it’s formatted.
Conclusion
Using MVC concepts in a React application creates cleaner separation of concerns:
- The Model handles data and business rules.
- The View handles UI and presentation.
- The Controller orchestrates state and user interaction.
This structure increases maintainability, testability, scalability, and overall software quality, especially as applications grow in complexity.
