Why do we use $conditions in sqoop?

The condition comes up with split but split automatically decides which slice of data transfers as every task. Condition force to run only one job ar a time and gives mapper to transfer data without any attack.

sqoop import --connect jdbc:mysql:// localhost/database_name --username user_name --password 1234 
--query 'select * from table_name where id=3 AND $CONDITIONS' --split-by table.id_no – m-1 target-dir /dir