I never coded on VS and I’m a junior programmer in C# and I would like to know if the entity framework is available only for ASP .NET applications ?
Not only. Entity Framework is an ORM for .NET applications.
Any time you want to bridge between an application and a database, you can use an ORM, including EF.
It is useful for WebForms, WinForms, WPF and other types of applications (using any .NET language).
No. It is suitable for any .NET application. ASP.NET WebForms and MVC websites, WinForms and WPF desktop applications, Windows services, console apps – anything. If you need to connect to a database, Entity Framework is the main Microsoft-endorsed way to do it.
Entity Framework (EF) is an Object Relational Mapper (ORM) for .NET Framework. You can use it in any application type. It has no dependency on your application User Interface (UI) type. It actually populates objects with data from your database and if you make any changes in your object then it saves that object data to database.
After getting the data in object form you can use that object in any type of application in .NET Framework like ASP.NET (WebForm and MVC), Windows Forms Application, WPF, Class library, Console Application etc.