Why should you care?

Shopping carts, "remember me", and preferences use cookies or sessions.

See it live — copy this example

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

Response.Cookies.Append("theme", "dark", new CookieOptions { HttpOnly = true });
HttpContext.Session.SetString("CartId", cartId);

Run Example »

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

What happened?

• Study the example line by line.
• Each part connects to Cookies vs Sessions.
• Edit one line, save, and run dotnet run to see what changes.

Try it yourself

1. Set a cookie or session value in one action.
2. Read it in the next request.
3. Clear it and confirm it is gone.
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

You learned what Cookies vs Sessions is and when to use it. Practice by changing the example yourself. Explain it in your own words before moving on.