What does the action dropdown in the Target Query do?

What options are available in the action button in Target Query?

There are multiple options in the action button which apply different rules to the target query. These are:

1. Members Update: Which updates the number of subscribers that meet the critiera set in the query chosen by you. This increases/decreases the number of members, depending on the data you have uploaded into the mail house, after the query was set up. 
2. Add to mail group: Allows you to place the members that meet the Target Query's criteria to be placed into a mail group.
3. Edit Target Query: If you are required to make changes to the Target Query, click this option to see previous set-up and continue to edit.
4. Delete Target Query: If the Target Query is no longer needed, you can delete it. If the mail group has been established, then you must also delete the mail group.