What is Interface?

Ans: Interface is the contract between programmer and technology. It Means that whatever the abstract method that a interface contain, you must override all (this is the contract).

Example:

Interface Contract
{
       void ContractHere();
}

class MakeContract : Contract
{
        void ContractHere()
        {
                Console.WriteLine("Contract Override Successfully");
        }
}
               

Why constructor is not inherit?

Inheritance said - only property and behaviour are inherited, and constructor is not a behaviour and not a property so that it is not inherited.

Difference between entity and object

Million Dollar Question. Differentiate entity and object.

Entities define the schema of an object but not the behaviour of the object. 

An entity has intrinsic identity while value objects is solely defined by the values of its properties.

We can also say that the abstract concept and the different representation are all entity(with their intrinsic identity). Here the representation refer to abstract concept.

But when we are come to object we are in consciousness.

Lets take an Example of Entity Framework in .Net,
where the database table is mapped through the entity and we can access the particular table by using the Object of these entity.

We also say that, an entity can be object but object can not be entity. Object usually refers to in memory data structures while entity is an abstract concept.

An Object has:
      1. Identity - a name
      2. State - determined by the values of its attributes
      3. Behavior - determined by how the object acts or reacts to requests (messages) from other objects

An Entity Example:
       1. Entity: Course
       2. Properties: Name, Location, Days Offered, Credit Hours, Professor