A super column is a tuple (a pair) with a binary super column name and a value that maps it to many columns.[1] They consist of a key–value pairs, where the values are columns. Theoretically speaking, super columns are (sorted) associative array of columns.[2] Similar to a regular column family where a row is a sorted map of column names and column values, a row in a super column family is a sorted map of super column names that maps to column names and column values.
A super column is part of a keyspace together with other super columns and column families, and columns.
Written in the JSON-like syntax, a super column definition can be like this:
"databases" are keyspace;
"Cassandra" and "HBase" are rowKeys;
"name" and "address" are super column names;
"firstName", "city", "age", etc. are column names.