Why should you care?

Without binding you would read Request.Form["Name"] by hand on every form. Binding keeps controllers readable.

See it live — copy this example

Create an MVC project (dotnet new mvc), add the code, and run dotnet run.

// GET /Products/Edit/5?id=5&tab=details
public IActionResult Edit(int id, string tab) { ... }

// POST with form fields Name, Price
[HttpPost]
public IActionResult Edit(ProductEditViewModel model)
{
    // model.Name and model.Price filled automatically
}

Run Example »

Edit the code and click Run — like W3Schools Try it Yourself.

What happened?

• Route {id} binds to parameter id.
• Form binds to model.Name.
• Binding runs before your action body; then check ModelState.IsValid.

Try it yourself

1. Add query parameter ?search=pen to Index and bind string search.
2. Build a POST form with name attributes matching ViewModel properties.
3. Rename a form field — watch binding fail and field come in null.
4. Change text or labels in the example and run again — watch the browser update.
5. Break the code on purpose (remove a semicolon), read the error message, then fix it.

Remember

Model binding maps HTTP data to C# objects. Names must match between HTML and properties. Always validate after binding.