The .NET SDK includes tools for building, testing, and publishing .NET applications, while the .NET runtime is required to execute those applications. In other words, the SDK is used during development to create applications, and the runtime is needed on the target system to run them. This separation allows developers to build applications that can be run on systems where the full SDK is not needed, such as production servers.

An essential property to set on the user object before calling the CreateAsync method in ASP.NET Core Identity is the Email property. The email address is typically used as a unique identifier for the user and is required for account recovery and communication purposes.

In earlier versions of ASP.NET Core, the project.json file was primarily used for managing NuGet package references. It provided a simple and convenient way to list and manage the dependencies required for a project, making package management more straightforward than using XML-based formats like the .csproj file.

The OnModelCreating method in Entity Framework Core is primarily used for defining the database schema. It allows developers to specify how the application's domain classes map to the database tables, including setting up relationships, keys, and other database-specific configurations. This method is essential for database initialization and migrations.

For mobile apps to communicate with a server, Web API is commonly used. It provides a RESTful way to fetch data and is well-suited for client-server communication in mobile apps.

Code-First Migrations in Entity Framework Core allows you to automatically create and update the database schema based on changes to your application's model. This feature is ideal for scenarios where the database schema evolves frequently to match the application's needs.

Entity Framework Core is primarily used for Object-Relational Mapping (ORM) in ASP.NET Core applications. It enables developers to work with databases using .NET objects, making database interaction easier and more intuitive. ORM helps to abstract the database details and allows developers to focus on business logic.

To facilitate file uploads in a Razor form, you would use the element. This input type allows users to select and upload files from their local storage.

Entity Framework Core employs automatic schema synchronization to handle database migrations. It automatically generates and runs SQL scripts to update the database schema to match the model changes. Developers don't need to write migration scripts manually, making it a convenient approach.

In the MVC (Model-View-Controller) pattern, the Controller is responsible for updating the view and processing user input. It acts as an intermediary between the Model (data) and the View (user interface). The Controller receives user requests, processes them, and updates the View accordingly.