Bulk SQL passes entire collections back and forth, not just individual elements. This technique improves performance by minimizing the number of context switches between the PL/SQL and SQL engines. You can use a single statement instead of aloop that issues a SQL statement in every iteration.

Bulk binding lets Oracle bind a variable in a SQL statement to a collection of values. The collection type can be any PL/SQL collection type (index-by table, nested table, or varray). The collection elements must have a SQL datatype such as CHAR, DATE, or NUMBER.
You can bind define variables in a dynamic query using the BULK COLLECT INTO clause. As the following example shows, you can use that clause in a bulk FETCH or bulk EXECUTE IMMEDIATE statement: