What are tuples in Python?

Tuples in Python are indeed defined as immutable sequences of values, which means that once a tuple is created, its contents cannot be changed. This immutability is a key characteristic that differentiates tuples from other sequence types in Python, like lists, which are mutable and allow for modification of their contents.

Because of their immutable nature, tuples can be used as keys in dictionaries and can also help protect the integrity of data that should not be altered after creation. Tuples can hold any type of data, including mixed types, and support various operations such as indexing and slicing similar to lists, making them versatile for many use cases.

The other choices describe features that do not properly represent tuples. For example, describing tuples as mutable sequences is incorrect since it contradicts their fundamental property of immutability. Likewise, suggesting that tuples are lists with predefined lengths or that they are arrays similar to lists fails to capture the unique characteristics of tuples in Python.