PL/SQL Developer, what does a little green tick called post changes do?

ORACLE  you haven't actually written to the database since you modified the data. If  you change the wrong, you can roll back.

Dot the green tick is write cache,   

Is the post meant to be transmitted? Change is what it means, you know.
Post changes is to pass the changes and not actually write to the database.  If someone queries the database at this time, they will not see what you have changed.  you are not actually writing to the database until you commit it.

This is  the concept of database transactions.

After you run the update Insert DELETE statement directly, the update is also not written to the database Ah, others can not find Ah, to execute a commit statement to really write into the database. This is the same as the submit button above.

PL/SQL Developer, what does a little green tick called post changes do?