From classic drag-and-drop Web Forms to contemporary MVC architecture and now to blazing-fast, cross-platform ASP.NET Core, ASP.NET has undergone tremendous evolution over the years. Developers may select the best technology for cloud solutions, SaaS products, enterprise applications, and APIs by being aware of the distinctions.

1. ASP.NET Web Forms
Overview
ASP.NET Web Forms (2002) follows an event-driven, server control-based model, similar to Windows desktop applications.
It uses ViewState to maintain UI state between requests.

• Key Features
• Drag-and-drop UI controls
• Rapid development
• Code-behind model
• Strong Visual Studio Designer support

Limitations
Heavy ViewState → slower performance
1. Not SEO-friendly
2. Tight coupling between UI & logic
3. Difficult to test (no clear separation)

Real-Time Use Case
Internal HR Management System (Leave request, employee attendance, salary slip portal)

Many legacy corporate internal portals still run on Web Forms because of rapid UI development & minimal front-end requirements.
Sample Code – Button Click event (Web Forms)

Default.aspx
<asp:Button ID="btnSubmit" runat="server" Text="Submit" OnClick="btnSubmit_Click" />
<asp:Label ID="lblMessage" runat="server" />

Default.aspx.cs
protected void btnSubmit_Click(object sender, EventArgs e)
{
    lblMessage.Text = "Request Submitted Successfully!";
}

2. ASP.NET MVC
Overview
Introduced in 2009, ASP.NET MVC follows the Model-View-Controller pattern, ensuring separation of concerns, testability & full control over HTML.

Key Features

• SEO-friendly
• No ViewState → lightweight
• Test-driven development
• Clean separation of concern
• Full control over HTML, CSS, JS

Limitations

• More coding compared to Web Forms
• Learning curve for beginners

Real-Time Use Case

E-commerce Application (Amazon-like portals)

• Product listing pages
• User login & cart management
• SEO-friendly product URLs (/products/shoes/sneakers)

Example – Return JSON response (MVC)
Controller
public class ProductController : Controller
{
    public ActionResult GetProduct()
    {
        var product = new { Id = 101, Name = "Laptop", Price = 55000 };
        return Json(product, JsonRequestBehavior.AllowGet);
    }
}

Overview
ASP.NET Core (2016+) is a cross-platform, high-performance framework designed for cloud & microservices architecture.
Key Features

• Runs on Linux, Windows, macOS
• High performance, lightweight
• Dependency Injection built-in
• Unified MVC + Web API framework
• Cloud-ready, container-friendly (Docker/Kubernetes)
• Minimal APIs for microservices

Real-Time Use Case
Online Trading / Banking API System

• Real-time stock market API
• Payment gateway integration
• Secure authentication (JWT, OAuth)
• Microservices workload

Banks, fintech & startups use ASP.NET Core for high speed + security.

Example – Minimal API (Core)
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/stock", () => "Stock Price: ₹102.55");
app.Run();

Comparison Table

Which Should You Choose?

Conclusion

ASP.NET's evolution shows how modern application needs have changed from simple web pages to scalable cloud-native systems. If you are starting a new project today → ASP.NET Core is the recommended choice.