MVC Architecture in 5 minutes: a tutorial for beginners
Model View Controller is a predictable software design pattern that can be used across many frameworks with many programming languages, commonly Python, Ruby on Rails, PHP, JavaScript, and more. It is popularly used to design web applications and mobile apps.
This blog post defines the concept of a Model-View-Controller (MVC) software design pattern and does a basic example Model-View-Controller in JavaScript/HTML/CSS.
Build your own web apps from scratch
Learn everything you need to know to build JavaScript web apps all in one place.
Complete JavaScript Course: Build a Real World App from Scratch
Javascript is one of the most prominent web programming languages that really made a difference. This course aims to be a useful companion for anyone wishing to (re)discover the many facets of JavaScript. Walk with us as we take you on a journey filled with all the wonders of Javascript including: - Basics of JavaScript with ES6 - How to traverse the DOM? - Modify Pages and handle events - Animate elements You will also learn how to build a Social News web application from scratch using the three web technologies HTML, CSS and JavaScript. Before moving on to advanced concepts, we will go through the fundamentals to get a strong grip over the basics. You can also experiment with the code provided and hence, gain a higher understanding of how things work. This course is perfect for anyone who wants to learn web development and get off to a good start in the JavaScript universe or catch up with its newest evolutions. Let's walk this (JavaScript) way!
What you'll build#
Before diving into Models, Views, and Controllers individually, it helps to see how MVC works in the context of a real application. Understanding the architecture is much easier when you can visualize the problem it is trying to solve.
Throughout this tutorial, imagine you're building a simple task management application. While the project is straightforward enough for beginners to understand, it contains many of the same architectural challenges found in larger software systems. Users need to create, update, view, and manage data, making it an ideal example for demonstrating how MVC organizes application logic.
By following this example, you'll see how MVC separates responsibilities, improves maintainability, and makes applications easier to scale as new features are added.
Project overview#
Our task management application allows users to organize and track their daily work through a simple interface.
Users can:
Create new tasks
Edit existing tasks
Delete tasks
Mark tasks as completed
View all tasks
Filter tasks by status (completed or pending)
Although this application is relatively small, it contains the same fundamental building blocks found in larger systems such as project management platforms, customer relationship management (CRM) tools, and productivity applications.
Why this project is useful#
This example strikes a balance between simplicity and realism.
It's simple enough that you can focus on understanding MVC concepts without getting distracted by complex business logic. At the same time, it's realistic enough to demonstrate how different parts of an application interact when users perform common actions.
As the application grows, new requirements such as user authentication, notifications, reporting, or collaboration features can be added without completely restructuring the codebase. That's one of the main reasons architectural patterns like MVC exist.
How MVC will power this application#
Component | Responsibility |
Model | Stores and manages task data |
View | Displays tasks to users |
Controller | Handles user actions and application logic |
Each component has a specific role.
The Model is responsible for storing and managing task information. It knows how tasks are created, updated, retrieved, and deleted.
The View is responsible for presenting information to users. It determines how task lists, forms, and status updates appear on the screen.
The Controller acts as the coordinator. It receives user requests, processes them, communicates with the Model, and decides which View should be displayed.
What happens when a user creates a task?#
The interaction follows a predictable flow:
User enters task↓Controller receives request↓Model stores task↓View updates task list↓User sees new task
Here's what happens behind the scenes:
The user enters a new task and clicks Create.
The Controller receives the request and validates the input.
The Controller asks the Model to save the task.
The Model stores the task in the database.
The Controller retrieves the updated task list.
The View renders the updated information.
The user immediately sees the newly created task.
This separation of responsibilities keeps the application organized and prevents business logic, data access, and user interface code from becoming tightly coupled.
Why this example matters#
The same MVC workflow appears in many applications you use every day.
Project management tools such as Jira and Trello
E-commerce websites
Social media applications
Banking dashboards
Content management systems
Whether a user creates a task, posts a comment, places an order, or updates a profile, the underlying flow is often remarkably similar: user action → application logic → data update → interface refresh.
That's why MVC remains one of the most widely used architectural patterns in software development.
Visual architecture overview#
The task management application can be visualized as follows:
Browser/User↓Controller↓Model↓DatabaseController↓View↓User Interface
Information flows through the system in two directions.
When users perform actions, requests travel from the user interface to the Controller and then to the Model and database.
When information needs to be displayed, the Controller retrieves data from the Model, passes it to the View, and the View renders the final interface shown to the user.
This clear flow of information is one of the key reasons MVC applications are easier to understand and maintain.
Skills you'll gain#
By the end of this tutorial, you'll understand:
MVC fundamentals | Forms the basis of many web frameworks |
Component separation | Makes applications easier to maintain |
Request flow understanding | Helps you debug and design applications |
Architectural thinking | Improves software design decisions |
Framework readiness | Makes learning MVC frameworks easier |
More importantly, you'll understand why MVC exists rather than simply memorizing its components.
MVC isn't just an academic pattern. Variations of MVC are used by frameworks such as Ruby on Rails, ASP.NET MVC, Spring MVC, Laravel, and many modern web applications.
Throughout the rest of this tutorial, we'll use this task management application to understand how each MVC component contributes to building maintainable software. As you explore Models, Views, and Controllers in more detail, you'll see how they work together to create applications that are easier to develop, test, and scale.
What is MVC Architecture?#
The architecture components of the MVC pattern are designed to handle different aspects of an application in development. The MVC design pattern serves to separate the presentation layer from the business logic.
Why do developers care about MVC? MVC is popular in app and web development, and it’s one of the most widely used software design patterns for app and web development. The Model View Controller design pattern separates concerns into one of 3 buckets:
- Model
- View
- Controller
The Model View Controller architectural pattern separates concerns into one of 3 buckets:
- Model: stores & manages data.
Often a database, in our quick example we’ll use local web storage on a browser to illustrate the concept.
- View: Graphical User Interface
The view is a visual representation of the data- like a chart, diagram, table, form.
The view contains all functionality that directly interacts with the user - like clicking a button, or an enter event.
- Controller: Brains of the application.
The controller connects the model and view. The controller converts inputs from the view to demands to retrieve/update data in the model.
The controller receives input from view, uses logic to translate the input to a demand for the model, the model grabs the data, the controller passes data from the model back to the view for the user to see in a nice display.
Benefits of MVC#
- Traditionally used for Graphical user interfaces (GUIs)
- Popular in web applications
- MVC responsibilities are divided between the client & server, compatible with web application architecture
- MVC is helpful design pattern when planning development
- Separation of Concerns: that code is divided based on function to either the model, view, or controller bucket
- Works well with Ruby on Rails
- Loosely Coupled
- Removes unnecessary dependencies
- Reuseable without modification
- MVC makes model classes reusable without modification
- Code reuse
- Extendable code
- High Cohesion
- Easier to maintain or modify
- Supports Multiple views
- Each part can be tested independently (Model, view, controller)
You can think of a web application as a Model View Controller design. MVC is popular in web applications, one of the reasons is because responsibilities are divided between the client & server.
Separation of Concerns#
MVC design allows for Separation of Concerns - dividing the logic up between the 3 buckets, so that each bucket can act independently.
The model, view, and controller don’t depend on each other. Why does this matter? Generally, software is worked on by teams - a team might have a designer, engineer, and database architect. Separation of concerns means each team member can work on their piece at the same time, because logic has been separated into buckets. Separation of concerns is also great for maitenance - developers can fix a bug in one piece of code, without having to check out the other pieces of code.
Loosely Coupled#
Loosely coupled means that each piece: the model, view and controller, act independently of eachother.
Developers can modify one of the pieces, and the other 2 pieces should keep working and not require modifications. When designing MVC software – the logic in each of the three buckets is independent. Everything in View acts independently of the model – and vice verse, the view won’t have any logic dependent on the model.
Making independent models and views makes code organization simple and easy to understand and keeps maintenance easier. Programmers can fix a bug in the view without changing the model code.
The pictures above show what happens in a MVC web app when a user clicks a button, from the perspective of the user.
Keep learning about web apps#
Learn the basics of JavaScript, DOM traversal, and event handling all in one place.
Educative interactive, text-based courses give you all the information you need in one place, without having to scrub through videos.
Complete JavaScript Course: Build a Real World App from Scratch
MVC Code Example#
For our simple example, we’ll store data in a browser. In a production quality web application – the data would be stored in a database.
Model#
In our Game of Thrones example the model is the fake database that lists the houses and characters. Normally, we don’t write this as a list in JavaScript, because GOT fans know that list can get real long, but this is the easiest way to demo on the blog.
View#
The view is what you see in the Output window - it’s a visual representation of the data displayed nicely for users. In our case a drop down list selector.
Controller#
The controller is the brains of our application - the JavaScript that handles the click event. The controller takes the event, processes it, and looks up the correct information from the model -in our example the members associated with each house. The controller returns the information to the view, for displaying.
Note: Before testing your code, please run the code by pressing the
RUNbutton. Then, you can click theTESTbutton. Otherwise, the test cases won’t pass.The code for this exercise comes from the Complete JavaScript Course.
What to learn next#
Congratulations on completing your first look into MVC architecture. Today, we covered the basics of MVC, covered the benefits and completed our own example project.
However, this is just one concept you’ll need to become a web app developer.
Some next topics to learn are:
- DOM traversal
- Page structure modification
- Advanced reactive events
- Animated elements
Happy learning!
