[]: Used to define mutable data types – lists, list comprehensions and for indexing/lookup/slicing.
(): Define tuples, order of operations, generator expressions, function calls and other syntax.
{}: The two hash table types – dictionaries and sets.
() parentheses are used for order of operations, or order of evaluation, and are referred to as tuples.
[] brackets are used for lists. List contents can be changed, unlike tuple content.
{} are used to define a dictionary in a “list” called a literal.