OAuth 2.0 is a powerful and secure framework that allows different applications to securely interact with each other on behalf of users without sharing sensitive credentials. The entities involved in OAuth are the User, the Server, and the Identity Provider (IDP).

Entity Framework (EF) is an object-relational mapping (ORM) framework developed by Microsoft for .NET applications. It provides a set of tools and libraries that allow developers to work with relational databases using .NET objects, eliminating the need to write low-level data access code, SQL queries, and database schema manipulation manually. Entity Framework supports various database systems, including Microsoft SQL Server, MySQL, PostgreSQL, and SQLite.

In many programming languages, you can prevent a class from being inherited by using the sealed (C#) or final (Java) modifier. This modifier restricts the inheritance of a class, ensuring that no other class can extend or inherit from it. Here’s an example in both C# and Java: