Why should you care?

Auth, logging, and error handling often belong in middleware so you do not copy the same code in every controller.

See it live — copy this example

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

var app = builder.Build();

app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

app.Run();

Run Example »

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

What happened?

• Order matters.
• Static files short-circuit before MVC if the file exists.
• Authentication runs before Authorization.
• MapControllerRoute is typically last among MVC middleware.

Try it yourself

1. Open Program.cs and read middleware top to bottom.
2. Comment out UseStaticFiles — see CSS disappear.
3. Add app.Use(async (ctx, next) => { Console.WriteLine(ctx.Request.Path); await next(); }); and watch terminal on each request.
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

Middleware runs in the order written in Program.cs. UseStaticFiles, UseRouting, UseAuth are standard. Custom middleware logs, headers, or exception handling.