Which of the following is a key characteristic of databases?

The key characteristic of databases being that data can be complex and interconnected is fundamental to their design and purpose. In databases, data is often organized in a manner that allows for relationships among different data sets. For example, in a relational database, tables can be related to one another through keys, enabling users to perform complex queries that join various pieces of information. This interconnectedness allows for a more comprehensive data analysis and retrieval process, reflecting the real-world relationships between different data elements.

This characteristic sets databases apart from simple data storage systems, where data might be stored in isolation without any relationship context, limiting the user's ability to derive insights or perform advanced data manipulations. By supporting complex data structures, databases can efficiently handle a wide variety of data types and relationships, making them invaluable for applications in numerous fields such as finance, healthcare, and social sciences.