Entity Framework Core (EF Core) is primarily used for managing database operations in web applications. It provides an object-relational mapping (ORM) framework, allowing developers to work with databases using .NET objects, thus reducing the need to write extensive SQL code.

In the "Startup.cs" file of an ASP.NET Core application, the "ConfigureServices" method is used to add and configure middleware services. Middleware services are components that handle requests and responses as they flow through the application's request pipeline. The "ConfigureServices" method is where you register services such as database connections, authentication, and dependency injection.

Entity Framework Core (EF Core) uses lazy loading proxies to enable lazy loading for navigation properties. To configure it, you can set the UseLazyLoadingProxies option to true in the DbContext's configuration. This allows EF Core to create dynamic proxies for your entities, enabling lazy loading for related entities.

To override the default routing conventions in ASP.NET Core MVC, you can use the "Route" attribute on your action methods. This attribute allows you to specify custom routing patterns, such as route templates and parameters, for fine-grained control over URL routing in your application.

To set up a route for a product details page with a product ID parameter using attribute routing, you should use [Route("products/details/{id:int}")]. The ':int' constraint specifies that the 'id' parameter must be an integer.

HTTPS (Hypertext Transfer Protocol Secure) is the recommended method for highly secure data transmission in Web APIs. It adds a layer of encryption (SSL/TLS) to the HTTP protocol, ensuring that data transmitted between the client and server is encrypted and secure from eavesdropping or tampering.

Entity Framework Core (EF Core) is primarily an Object-Relational Mapping (ORM) framework. It simplifies database operations by allowing developers to work with databases using object-oriented code, making it easier to interact with and manipulate data. User authentication, web hosting, and front-end development are unrelated to EF Core's core functionality.

To send binary content as the response in ASP.NET Core, you should use the FileResult action result. This result type allows you to send files, such as images, PDFs, or any binary data, in response to a client request. You can specify the file's content type, name, and other details.

While Eclipse is a powerful IDE mostly known for Java development and other types of development, it's not typically used for ASP.NET Core development. Tools like Visual Studio, Visual Studio Code, and Rider provide integrated support for ASP.NET Core.

To apply a unique constraint on a column in Entity Framework Core using the Fluent API, you should use the IsUnique method. This method ensures that the database enforces uniqueness for the specified column or columns, preventing duplicate values from being inserted. It's a crucial feature for maintaining data integrity.