A clustered columnstore index physically reorganizes a table. The data is divided into a series of rowgroups of up to 1 million rows (approximately) that are compressed to improve I/O performance. When querying data by column, the data warehouse simply needs to read the column segments for that column. Decompression is performed quickly in memory, and the results returned to the query.
With clustered columnstore index over a table, entire table is indexed.
CREATE TABLE clusteredColumnstoreTable ( id int NOT NULL, firstName varchar (50), lastName varchar (50), zipCode varchar (10) ) WITH (CLUSTERED COLUMNSTORE INDEX);
More information - https://docs.microsoft.com/en-nz/sql/relational-databases/indexes/columnstore-indexes-overview?view=sql-server-ver15