Is there a difference between connecting to the bank using a class and through visual studio: ToolsConect_to_database? [closed]

They serve for different things in Visual Studio database attachments to create and administer (create database logic like relations tables etc ...). In your application you will call to enter and process the data. The logic will be in VS you create the table and its fields ... in the application you insert the data provided by the user in the database respecting the structure that you created in VS.

Friend, it depends on how you design your application. I'm working on a C # Winforms application and I'm using the Code First methodology. Therefore, every connection process is done via code. I do not have visual objects connected. If you are developing Delphi style, you can connect via objects on the design screen, but I have no experience with this mode.

I do not know who gave -1 in your question, I find it unnecessary, since it is a beginner's doubt.