Hello All,
Hope you are well?
Thanks for your clear answer for my previous questions.
am beginner in database and I want to know about the following:

1. What is the three stages in the process for developing database systems?

2. What is the difference between an entity class and an entity instance?

3. What is an object-relational database, and how does it differ from a relational database?

and I will be happy if you can give me any website or referance for Database articles.

Thanks and Regards