.NET COBOL is regular procedural COBOL with extensions to take advantage of the features of the managed frameworks such as .NET. This includes object-oriented (OO) syntax that allows access to large libraries of functionality you can use in your application, and much more. To take full advantage of .NET COBOL, it is helpful to understand the object-oriented concepts.
A guide that provides a basic introduction to Object-Oriented Programming (OOP) for COBOL developers, An Introduction to Object-Oriented Programming for COBOL Developers, with examples, is available from the Micro Focus Customer Support Documentation Web site.