To prevent a Razor form from being submitted if client-side validation fails, you can use the onsubmit attribute on the form element. By specifying a JavaScript function that returns false when validation fails, you can stop the form submission and show validation errors to the user.

In ASP.NET Core, the [Route] attribute is used to define the route template for an action method. This template determines how the URL should be structured to access the method. For example, [Route("api/products")] specifies that the method should be reachable at the URL "api/products."

In ASP.NET Core, you can fetch the username of the currently logged-in user by accessing HttpContext.User.Identity.Name. This property contains the username of the authenticated user, allowing you to display a personalized greeting like "Welcome, [Username]!".

The [Authorize] attribute in ASP.NET Core is primarily used for Authorization, not Authentication. It restricts access to a particular action method or controller to only authenticated users who meet specific authorization requirements. This helps in controlling who can access different parts of your application based on roles or policies.

When defining a one-to-many relationship in Entity Framework Core, the HasMany method is commonly used to represent the "many" side of the relationship. This method allows you to specify the navigation property on the "one" side and configure various aspects of the relationship, such as cascading deletes and foreign key constraints on the "many" side. It's an essential part of modeling complex database relationships.

In ASP.NET Core MVC, the default convention for locating views is in the "Views" folder within the project's directory structure. Views contain the markup and templates used to generate the HTML or other output sent to the client's browser.

ASP.NET Core routing uses a first-match-wins strategy. In this case, the incoming request "/products/new" matches the second route "/products/new" exactly. Therefore, it will not proceed to check other routes and will be handled by the "/products/new" route.

In ASP.NET Core, configuration settings can be stored in various JSON files, such as "appsettings.json" for general settings. However, when deploying to production, the configuration values in "appsettings.Production.json" take precedence over those in "appsettings.json." This allows developers to maintain separate configurations for different environments.

The "Email Confirmation" feature in ASP.NET Core Identity allows users to verify their email addresses before gaining full access to the application. This is crucial for scenarios like e-commerce websites, ensuring that users have valid and verified email addresses before making purchases.

ASP.NET Core introduced a flexible and extensible configuration system that allows developers to configure applications using various sources, such as JSON, XML, environment variables, command-line arguments, and more. This approach offers better configurability and ease of use compared to the traditional ASP.NET configuration methods.