Cassandra CQL collections help you to store multiple values in a single variable. In Cassandra, you can use CQL collections in following ways:
List: It is used when the order of the data needs to be maintained, and a value is to be stored multiple times (holds the list of unique elements)
SET: It is used for group of elements to store and returned in sorted orders (holds repeating elements)
MAP: It is a data type used to store a key-value pair of elements