What are OOPS concepts? The main concepts of OOPS used in D365 FO are: Class and Objects Data Abstraction: Showing only the essential information and hiding background details. Encapsulation: Wrapping of data member and method to a single unit. Inheritance Flowing of property of the parent class to the child class. Polymorphism is the property of repeatedly using the same method to perform different things. Interfaces & Abstract Class The class implementing is the interface that implements all interface methods and there will not be any abstract Class requirement. There are many access modifiers available like abstract, protected, virtual, internal, public, and many more that are useful in the abstract Classes. Abstract classes will be very fast when compared to interfaces. Interfaces Abstract Class The interface is the signature for a particular method. Abstract cl...