These step, You can choose whether you will extract the database in the form of a "structure only" or "sctructure and data".
DDL (Data Definition Language) and
DML (Data Manipulation Language), used to defining data structures or database schemas.
If you check the "Generate bulk INSERT Statement", will have an effect to the extract file size becomes smaller, but it would be at risk on big data, when restoring data extract.
By removing the check in the "Generate bulk INSERT Statement", the size of the extracted file will be larger but, to be safe when we will restore the database because each row will be executed one by one.