The primary role of "_Layout.cshtml" in ASP.NET Core is to define the webpage's structure and common elements, such as the header, footer, and navigation menu. It allows for consistent layout across multiple pages in your application.

The .NET CLI (Command-Line Interface) is a powerful tool for building, running, and managing .NET applications without relying on a full-fledged Integrated Development Environment (IDE). It allows developers to work efficiently in the command-line environment, making it a versatile choice for various .NET development tasks.

When using client-side validation in Razor forms, the unobtrusive Validation library is frequently used in conjunction with jQuery. This library allows you to define validation rules for form fields on the client side, providing immediate feedback to users without requiring a server round-trip. It's a crucial component for building responsive and user-friendly web applications.

Routing in an ASP.NET Core MVC application is typically configured in the Configure method of the Startup.cs file. This method sets up the request processing pipeline, including routing rules for different URL patterns.

The ASP.NET Core MVC template is ideal for creating a simple blog. It provides built-in features for handling user comments and posts. MVC (Model-View-Controller) is a pattern that separates the application into components for managing data, the user interface, and the control flow, making it suitable for this scenario.

The NuGet Package Manager is the component of the ASP.NET Core development environment that handles dependency resolution and package management. It is a powerful package manager that helps developers manage and integrate third-party libraries and packages seamlessly into ASP.NET Core projects.

In integration testing, it's common to mock HTTP requests. This ensures that the tests don't interact with the real database or external services, preventing unintended side effects on actual data during testing.

To enforce strict null checking in Razor views, you can enable nullable reference types by using the "#nullable" directive at the top of your Razor file. This allows the compiler to detect potential null reference issues at compile-time, reducing runtime errors.

The _ViewImports.cshtml file is responsible for defining common using directives and shared code that are automatically available to all Razor views in an ASP.NET Core project. It centralizes the configuration for views, promoting code reuse and consistency.

The ASP.NET Core project definition is primarily saved in a .json (JavaScript Object Notation) file format. This JSON file, often named "project.json" or "*.csproj," contains essential project configuration information, dependencies, and build settings. It's used by the build system to compile and manage the project.