Just as you might expect, the “trash” option in WordPress is where you can place files that you no longer need. If you’re used to using a Windows operating system on your computer, the WordPress trash option functions just like the Recycle Bin. If you’re using a Macintosh operating system, the WordPress trash is just like the Trash on your computer.
Note: In order to put a file in the WordPress trash, you must have the right permission level, which is determined by what kind of user you are. You must be an Editor, Administrator, or Super Admin in order to put a file in the WordPress trash.
Assuming you have the user level ability to do so, every time you delete a page, a post, or a comment, it is automatically moved to the WordPress trash. The item will remain in the trash for 30 days. After 30 days, the item will be permanently deleted from your system and will be impossible to recover.
In case you have mistakenly deleted an item, you can restore it from the trash as long as the 30 days have not yet passed.
The trash function was added to WordPress 2.9 and is included in all newer versions. If you are using an older version, any deleted files will be immediately and permanently erased from your system.