Cobol is mainly used in a business environment where architectures use the IPO principle: Input some data (records in a file), process them and output them (print records). Off course, this is a very simplistic view.  

This IPO principle is still found in most modern system architectures and is sometimes synonimized with client-server architecture.  Fact is that input forms got smart as http-requests, and printed reports went also intelligent in the form of html-pages. From a Cobol perspective these smart entities are a foreign concept since they are in free format.