This content originally appeared on DEV Community and was authored by Zamirul Kabir
MVC (Model–View–Controller) — detailed, plain English
What it is:
MVC is a software design pattern that splits an application into three responsibilities to make code easier to understand, test, and maintain.
Parts & role
Model — holds the data and the business rules. Think: database records, validation logic, and how data is transformed. It’s the source of truth.
View — the user-facing presentation layer. HTML, mobile screens, or UI components that display Model data.
Controller — the mediator that receives user input (clicks, form submits), talks to the Model to read/update data, and picks which View to render.
Typical request flow (web example):
- User clicks a button in the View.
- Controller receives the request/route and validates input.
- Controller asks the Model to fetch/update data.
- Model returns data (or an error).
- Controller chooses a View and passes the Model data to it.
- View renders the final UI the user sees
Benefits
- Clear separation of concerns → easier to maintain and scale.
- Easier to unit test Models and Controllers.
- Multiple Views can reuse the same Model (e.g., web + mobile + API).
Drawbacks/caveats
- If misapplied, Controllers can become “fat” (too much logic). Keep business logic in Models or service layers.
- Not a silver bullet — for very small apps, it may add unnecessary structure.
When to use
- Apps with complex UI and logic (web apps, admin dashboards).
- Teams that want clear ownership of UI vs business logic.
- Systems that need multiple presentation layers (web + mobile + API).
Practical tips
- Keep Controllers thin: orchestrate, don’t contain business logic.
- Move shared business logic into services or the Model.
- Use View models (DTOs) to shape data for UI and keep Views simple.
Client–Server Architecture — detailed
What it is:
A networking model where clients (users’ devices or apps) request services and servers (central machines) provide them. It’s the backbone of almost all modern networked apps.
Parts & role
- Client — the consumer (browser, mobile app, desktop app). It initiates requests and renders responses.
- Server — the provider (web servers, application servers, database servers). It processes requests and sends responses.
- Communication — usually HTTP/HTTPS, sockets, or other protocols.
Modes
- Stateless (HTTP typical): Each request is independent (easier to scale). Use tokens or cookies for auth.
- **Stateful: **server keeps session state (useful for certain real-time apps but harder to scale).
Typical flow (HTTP):
- Client sends request (GET/POST/etc) to server.
- Server authenticates/validates the request.
- Server processes business logic and/or fetches data.
- Server responds with data (HTML, JSON) or an error.
- Client renders or acts on the response.
Benefits
- Centralized control of data and logic.
- Easier to secure and update (update the server, clients benefit immediately).
- Scales well with stateless requests and horizontal server scaling.
Drawbacks/caveats
- Single-point-of-failure risks (mitigate with load balancers, redundancy).
- Latency — user experience depends on network round-trips.
- Complex scaling for stateful services (session replication, sticky sessions).
When to use
- Almost every web and mobile application. It’s the default pattern.
- Systems needing centralized data management, unified business logic, or controlled access.
Best practices
- Use HTTPS for every request.
- Prefer stateless APIs (REST / JSON) for scalability; use WebSockets or gRPC for real-time.
- Cache aggressively (CDNs, server-side caching) to reduce latency.
- Design APIs with versioning and clear contracts.
- Plan monitoring, autoscaling, and redundancy from day one.
Quick comparison — MVC vs Client–Server
Scope: MVC is a software design pattern for organizing code inside an application. Client–server is a network architecture describing how machines interact across a network. They operate at different layers and are often used together (an MVC app deployed on servers communicating with clients).
**Use together: **A web application can implement MVC on the server (or client) side while using the client–server model to serve requests to browsers or mobile apps.
Examples (real-world)
MVC example: A blog platform’s server uses MVC: Model = Post/Comment objects, Controller = routes handling create/edit, View = template pages.
**Client–Server example: **A mobile app (client) calls REST endpoints on a cloud service (server) to fetch user data; the server talks to a database and returns JSON.
This content originally appeared on DEV Community and was authored by Zamirul Kabir
Zamirul Kabir | Sciencx (2025-11-06T00:50:40+00:00) MVC and Client-Server Details. Retrieved from https://www.scien.cx/2025/11/06/mvc-and-client-server-details/
Please log in to upload a file.
There are no updates yet.
Click the Upload button above to add an update.