How are entries in a dictionary defined?

Entries in a dictionary are defined as key/value pairs. In Python, a dictionary is a built-in data type that allows you to store data in an organized way, using keys to access corresponding values. Each key is unique within the dictionary, and it serves as an identifier for the value associated with it. This structure enables efficient data retrieval, as you can quickly find a value when you know its key.

A dictionary's key/value pair organization is particularly useful for situations where you want to pair related data together. For example, in a dictionary representing a contact list, you might use a person's name as the key and their phone number as the value. This provides a clear mapping that is easy to understand and work with programmatically.

The other choices highlight aspects that are not characteristic of a dictionary. A list of indexed items refers to a list, which is ordered and accessed by index rather than keys. Unique strings do not adequately describe dictionaries as keys can be strings, integers, or tuples as long as they are immutable types. A set of unordered items refers to sets, which do not store key/value associations but rather just unique items. Understanding these distinctions helps clarify the unique and functional role that dictionaries play in Python programming.