Bulk Bind is technique where instead of multiple individual
SELECT, INSERT, UPDATEE & DELETE statements are executed to
retrive from or store data in, at table all of the
opeartions are carried out at once in bulk.

Regard's
Srinivas Ganamur

Binding of entire collection at once is called as " Bulk 

Bind".

Bulk binding is a way for performance tunning i.e. it will 
complete the whole process in once remove the contaxt 
switching of sql to pl-sql & pl-sql to sql.

A DML statement can transfer all the elements of a
collection in a single operation, a process known as bulk
binding. If the collection has 20 elements, bulk binding
lets you perform the equivalent of 20 SELECT, INSERT,
UPDATE, or DELETE statements using a single operation. This
technique improves performance by minimizing the number of
context switches between the PL/SQL and SQL engines. With
bulk binds, entire collections, not just individual
elements, are passed back and forth.