When you drag the Announcement list block underneath a sub-site, you will be prompted with a dialogue box with the following:
List Name: This gives a name to the list. When you create the list, this is the name that will be assigned to the list upon creation.
Description: This allows you to be able to create a description for the list allowing other users to know what the list is being used for.
In addition, on the second tab, if you have knowledge of powershell script, you are able to add extra columns or features to the list via the powershell code editor.
When the Announcement list is created, it is given the following columns:
Title: This allows you to put in a title for the announcement list.
Modified: This field will auto update to include the last modified date for the announcements list.