Dictionaries in data structures are a type of associative container that store data in key-value pairs. Each key in a dictionary is unique, and it’s used to access its corresponding value. This structure allows for efficient lookups, additions, and deletions because keys are typically hashed, which enables quick retrieval of values based on their associated keys. Dictionaries are flexible and can store various data types as values, such as numbers, strings, or even other dictionaries. They are widely used in programming for tasks where quick access to data based on specific identifiers is crucial, such as in implementing lookup tables or managing configurations.