OS X Mountain Lion: Delete files from your Mac
You can get rid of files, folders, and other items that you no longer need.
If you turned off Time Machine and don’t back up your files, before you remove an item you may want to store a backup copy on a CD, DVD, or other storage device, just in case you change your mind and want to retrieve the item later.
- To remove an item, drag it to the Trash. The Trash is located at the end of the Dock.
- Choose Finder > Empty Trash.
- When you see a warning message, click OK.
Tip: To prevent the warning message from appearing, press the Option key when you choose Empty Trash. You can also turn off the warning in the Advanced pane of Finder preferences.
Even after you empty the Trash, deleted files can be recovered using data-recovery software. To delete files so they can’t be recovered, see this help topic:
Prevent deleted files from being read
You can also use Disk Utility to securely remove items from your computer.