Php/docs/cubrid.resources
From Get docs
Resource Types
There are four resource types used in CUBRID. The first one is the link identifier for a database connection, the second is the a resource which holds the result of a query, and the last two a resource which holds the query results of BLOB/CLOB data types.
connection identifier
A connection identifier returned by cubrid_connect(), cubrid_connect_with_url(), cubrid_pconnect() and cubrid_pconnect_with_url().