Final answer:
A system that allows for easy combination and manipulation of data, which can be difficult with separate files, is a Relational Database Management System (RDBMS). It manages data in tables that can be linked through keys, facilitating the retrieval and management of related data across tables.
Step-by-step explanation:
A system that provides the user or the user's application software the ability to combine and manipulate data easily in ways that would be difficult with separate and unrelated files is known as a Relational Database Management System (RDBMS). The RDBMS is designed to manage large sets of data that are organized into tables. These tables can be linked or related based on common data known as a key. This relationship between tables enables users to retrieve and manage related data across different tables easily. For instance, a retail business could use an RDBMS to manage data across separate tables for customers, orders, and products, and the system could rapidly provide a comprehensive view of the customer's order histories by combining these related pieces of data.