………. is defined as a set of related data or information that is being stored in secondary storage.

The term that fits the definition of "a set of related data or information that is being stored in secondary storage" is Database.

A database is a structured collection of data that enables easy access, management, and updating of the information it contains. It is designed to store data in a way that allows for efficient retrieval and modification. Databases are used in various applications, from business and finance to education and healthcare, to manage vast amounts of information.

In secondary storage, which includes devices like hard drives, SSDs, and cloud storage, databases can be stored in various formats, such as relational databases (using tables to organize data) or NoSQL databases (which can store unstructured data). The management of a database is typically handled by a Database Management System (DBMS) which provides an interface for users to query and manipulate the data.