What is ERD????

Hey guys in my previous post I show the tutorial on how to make an ERD.But now I am gonna go a little bit deeper in this topic.

First of all my question is what is ERD.Well you can say that it is a short form for Entity Relationship Diagram.Well it is basically just a diagram to arrange your data properly in order to make it easier to understand.ERD is more like a preparation before you create any system.

But what is Entity?
Entity is an object or concept that is unique and can be recognised in your daily life such as

students, teachers, books or examination

Well that just an example if you want to create a system based on school.

There are also two types of Entity which is strong entity and weak entity.

As you guys see on the picture above strong entity can exist without the existence of other entity.on the other side weak entity can only exist if there is a strong entity.Weak entity is more like a support while the strong entity is the main important thing in ERD.

Thank you very much guys.On my next post I will tell you guys about attributes in ERD.And again I am sorry if they are any grammar mistake in my post.